New Possible Supernova in NGC1365

[Park123]

Hi all,
I wanted to let people know of a new possible supernova that has just been discovered. Even though I didn’t discover it I did help in confirming the new target.It was discovered by A. Klotz on behalf of the TAROT Collaboration.
It is in NGC1365 a 9.5 mag fantastic looking galaxy in Fornax.
Here is my confirming image at this link

http://www.bosssupernova.com/confirmingimages.htm

It currently sits at mag 15.10 and rising fast. This could be the supernova of the year and makes a fantastic target for astro imagers.
This new target will be typed by the professionals in the next day or so and if it is a type Ia could reach a peak mag of 12.5-13 well in range of small telescopes.
Bob Evans found supernova 2001du in this galaxy which was confirmed by Greg Bock a BOSS member.
It seems the BOSS group always get second with discoveries in this fine galaxy!!!!!

This will be a great target to follow in the coming months


Stu Parker


For BOSS-Backyard Observatory Supernova Search


:eyepop::eyepop::eyepop:

[astroron]

Should be a beauty Stu :D
Thanks for letting us know .:thanx:
Cheers:thumbsup:

[andyc]

Very exciting indeed! I'll look forward to trying to find this if it brightens up a bit :thumbsup:

[Nico13]

Thanks Stu, a good confirming shot. :thumbsup:

Was just looking at Fornax last night on TheSky6 for upcoming targets over the next few months and this galaxy was put on my list so now I'm doubly sure to take a look and some images.

[jjjnettie]

Excellent news. :)

[mental4astro]

One to hunt down visually from home! Will also provide a gauge for viewing conditions.

Many thanks for the posting Stu.:)

[Terry B]

I tried last night hoping to take a spectra of it but there was too much cloud. Same forecast tonight. Hopefully it clears soon.

[Paul Haese]

I started shooting this a couple of weeks ago and there was no sign of it then. Missed it by that much as max would say. Thanks for the heads up.

[Rob_K]

An ATel has been posted, indicating that from a spectrum obtained on 28.53 Oct it is a young type 1a supernova about 11 days from maximum:
http://www.astronomerstelegram.org/?read=4525

Cheers -

[lepton3]

This is a very large photogenic galaxy. Even at f/5 it is bigger than the sensor in my Atik320E camera.

Full moon is probably not the best time for a pretty astro image, but give it a week or two and I expect we will see some amazing images.

Meanwhile, if the weather cooperates, I will try an image tonight through an R filter for photometric purposes.

-Ivan

[avandonk]

Took a few shots centred on NGC1387 60sec lum, unguided. There was a full Moon present! I did not bother with darks or flats.

Here is a full res single exposure 3MB

http://d1355990.i49.quadrahosting.com.au/2012_10/ngc1387.jpg


Below are a few Registar images to show where the SN is.


Bert

[lepton3]

Here's an image of the PSN fresh from the 'scope. A total of 1hr exposure at f/5.

The R filter was mandatory with the full moon. I measure the R Mag at 14.2

This SN is rapidly rising. Over the 1 hr it brightened by 0.025 mag.

-Ivan

[avandonk]

Here is a stack of ten 60s images corrected for darks and flats. 4MB

Also with a map below.

http://d1355990.i49.quadrahosting.com.au/2012_10/ngc1387_.jpg

Bert

[Paul Haese]

Just for comparisons here is some data I shot on the 14th of October. With later shots you can doa blink and see where the SN is located. I hope this is helpful to you guys.

edit, from my image it looks like this might have been a blue giant that exploded. There appears to be a faint blue star in my image in the same position.

[Merlin66]

Here's a copy of the NGC 1365 sheet from Gregg Thompson's SN Search charts. (One I checked for him in the early 1980's)

[Greg Bock]

Yes, i just missed out on finding this one the day before it was discovered.
I was imaging SN target galaxies in the area nearby, but high winds and cloud forced me to close up before i resched NGC1365...doh....very annoyed!

It would have been fantastic to have discovered this one after doing the confirmation of 2001du for Bob 11 years ago...oh well, i'll just have to keep monitoring it and hopefully get the next one...

[Rob_K]

Good stuff Paul - I created an animation using your shot & Steve's. Yours doesn't appear to show anything at the position but this is valuable anyway as you have stars in the image down towards mag 18, maybe dimmer if you really searched.

Cheers -

[Paul Haese]

Cool Rob.

The blue star I was talking about is just a tad off to the lower right. That star came out of that "vacant space".

[Terry B]

Despite crappy cloud I was able to get 30 min of cloud affected spectra of this tonight. Shows broad absorptions.
Cheers
Terry

[Merlin66]

Terry,
Well done!
Maybe noisy, but it clearly shows the deep silicon absorption around 5900A.
The attached illustration shows the different "markers" used to identify Type I and Type II SN.

[lepton3]

Terry, that is exceptional work. I can see clearly the Iron, Sulphur and Silicon features of a type Ia supernova in that spectrum.

Incredibly impressive.

-Ivan

[LewisM]

Here's my NGC 1365 from about 2 weeks ago:

http://imageshack.us/f/62/fornaxgroupngc1365.png/

[LewisM]

Here is a cropped single 3 minute sub at 100%, pre-SN.

[Greg Bock]

Terry, Ken
thanks a bunch guys for posting your info on the spectrum, very informative indeed. :) Keep it up!

[LewisM]

Taken the first 5 subs (5 mins, with a full moon no less) and it is VERY apparent! YEEHAW!

[cometcatcher]

Looks like about magnitude 13 now very rough estimate.

[Greg Bock]

Hi all,
here's an image taken tonight, the new SN is about magnitude 13.3 V.
Bright moonlight created the annoying bckground...

[LewisM]

Best I could do with an ED127 refractor tonight, smack bang in the middle of suburbia with that darned moon!

[Larryp]

Pretty good, Lewis!

[mental4astro]

Lewis, I'll be using your photo as a guide to 1365 from home if I can manage an evening WITHOUT clouds. I should be able to star hop to it incase I can't make out too much of the faint fuzzy. I'll use my 8" dob, and hopefully my 17.5 if the sky looks good. With the Moon about this still shouldn't be a problem. I've seen 1365 from a dark site, and it is stunning, but I haven't tried from home.

[Glenpiper]

Thre are more amateur spectra and comment, including GELATO's 1a type confirmation of this SN, with Terry's and my spectra, in the ARAS forum at http://www.spectro-aras.com/forum/viewtopic.php?f=6&t=465

Cheers,

[mental4astro]

Q. where can I find info on Type I & II supernovae? I don't know the difference between them.

[Merlin66]

Kaler's "Stars and their spectra', 2nd ed, pages 366 -376.
then
Gaposchkin's "The galactic Novae", page 259-285

Executive summary:
Type I - No hydrogen absorption/emmison
Ia - strong SII
Ib - none of the above, but HeI
Ic - lines of light elements ie oxygen and calcium
Type II - Hydrogen lines emmision and/or absorption
All have different light curves
Type Ia - can be found anywhere in the galaxy/ halo (Population II)
Type II -on in the disk (Population I)
See also:
http://en.wikipedia.org/wiki/Supernova
HTH

[Terry B]

From last night.
magnitude
B = 13.50
V = 13.47
R = 13.43
I = 13.54

The image is through a V filter
The spectra is a comparison with a type 1a sn

Cheers

Terry

[cometcatcher]

Wide field shot through a 5" F5 refractor, 15x2 mins.

[Greg Bock]

Very nice Terry, agrees well with my image above taken 2 days ago.

[JohnG]

Taken at around 0945UT, 01/11/12.

Very windy, 5 x 250 seconds @ -25c with the Takahashi FSQ-106ED at f/5.0. No Flats or Darks, very limited Levels and Curves.

Cheers

[Merlin66]

John,
Well done!
That's a VERY nice image!

[LewisM]

Interesting new astronomer telegram:

ATEL #4535 ATEL #4535

Title: Type-Ia SN 2012fr: no progenitor detected in pre-explosion
HST image to M_V ~ -5.9 mag
Author: Or Graur (Tel-Aviv U., AMNH), Dan Maoz (Tel-Aviv U.)
Queries: maoz@astro.tau.ac.il
Posted: 1 Nov 2012; 22:01 UT
Subjects:Optical, Supernovae

We have analyzed archival Hubble Space Telescope WFPC2 images of NGC 1365
in F606W (~ V band, 560 s total) from 2001. We detect no sources within
a 0.5'' radius of the location of the Type-Ia supernova SN 2012fr (PSN
J03333599-3607377, ATel#4523), as determined by registering the HST images
with images of the SN by Stu Parker and by Ivan Curtis (see http://www.rochesterastronomy.org/snimages),
using two bright stars near the SN. By planting fake point sources at the
location of the SN, we obtain a 2-sigma flux limit of 25.3 mag in F606W.
The Tully-Fisher-based distance modulus of NGC 1365 is 31.16+/-0.35 (Tully
et al. 2009, AJ, 138, 323), and the Galactic extinction in this direction
is A_V=0.056 (Schlafly et al. 2011, ApJ, 737, 103). Barring the possibility
of extinction in the host galaxy, a progenitor or companion of SN 2012fr
was therefore fainter than M_V ~ -5.9 mag, ruling out the presence of supergiants
of such luminosity at the explosion site. An image showing the searched
region of the HST data is at http://www.astro.tau.ac.il/~orgraur/sn2012fr.jpg

[LewisM]

Took another single 300sec sub last night before my camera batteries decided to die (idiot forgot to recharge them!). Less than dark suburbia, as usual.

[Terry B]

Well done. At least you got an image.I went out a 9pm last night and there were lots of stars to the south. As I walked outside I felt rain. Clear to the south and rain overhead. Very annoying.

[cometcatcher]

Looks like it's getting brighter. At least brighter than the star next to it. I do find this exciting though as it's only my second supernova.

Not an easy thing to image in the tropics when it's 30C, hazy and the camera isn't cooled. Video capture through a 5 inch F5 from last night.

[LewisM]

Nothing but cloud and dust haze here on the "Sunshine Coast".

Darned thing will be waning before I get another go

[lepton3]

Here's the latest R-band photometry. Now at R magnitude 12.4! This is going to be a beauty.



Don't worry, we're probably still a week from peak!!.

-Ivan

[entity62]

Took these live/ semi live views last night The first pic is a live view, using a Mallincam video camera, the rest have intergration times.
SCT 11in with a MFR5 focal reducer

[cometcatcher]

Last night's pic with the 5" F5. I need a bigger scope to image with. Do you guys reckon my EQ2 will hold my 16 inch dob? :question: :lol:

[LewisM]

Tonight (4 November, 2012), the SN is VISIBLY much brighter in magnitude than previously, and noticeably brighter than the star near it (close to the spiral arm).

Photos later... trying to get some in between clouds.

[LewisM]

Field edit shot. Also, noticing the "bar" artifact under the SN, looking like an extra spiral arm (appearing in ALL the shots)

[LewisM]

Another, now with darks subtracted in camera

[wayne anderson]

NGC 1365

I could visually see the S shape structure of this Galaxy and the Super Nova.
Time available to me was very short this week so this is a quick one to see what it was like, hoping to get more time to image this weekend at a darker site.

40 x 25 sec subs
Stacked in DDS no darks or flats just tone curve adjustments crop and resize
12” LX200 (alt/az setup) Sony Nex-3 camera

[Greg Bock]

HI guys,
FWIW, I managed to get a 17 minute image last night during a break in my supernova search program.SN2012fr is still on the rise.

[lepton3]

Greg,

A beautiful photo, nicely processed. Is it possible for you to measure a magnitude from your unprocessed image?

I was hoping to follow this one, but we are clouded out here in Adelaide.

-Ivan

[Greg Bock]

Hi Ivan, yes of course, but i will have to wait until i get home from work, or maybe at lunchtime. I processed it quickly this morning so I could post it here, but didnt really have enough time to measure the brightness properly.

[Terry B]

I took BVRI images and a spectra 2 nights ago but haven't reduced them yet. I will post the results soon.

[Greg Bock]

Guys,
Magnitude estimate from a 5 minute subframe that was used in my 17 minute image last night, 5/11/12.
Using SkyX and CCDSoft, checked with MaximDL, I get 13.1 to 13.4 using UCAC3 reference stars.

[m@s]

Wow, Greg, your 17 minute image is great !
Thank you for sharing :)

Marc.

[pvelez]

Can't wait to seethe spectrum Terry

Pete

[pvelez]

Greg

that is a lovely shot - good and crisp.

Pete

[astroron]

Greg Seems a lot brighter to me:shrug:
I would put it at the back end of mag 12 at least.
I could see it quite easily in my 8"SCT with a 21mm plossl.
But I bow to your greater knowledge of magnitudes from images:)
Cheers:thumbsup:

[Greg Bock]

HI Ron,
yes, i measured a range of values of field stars as well as the SN to arrive at those values above, and I recall measuring one value for the SN of 12.8 at one stage, but it was in the minority so I dropped it.

Please rest assured that I'm not expert here, but I do know there are traps and pitfalls that can make the process difficult to get the correct result. I checked and re-checked my estimate with the tools as I noted above, so i was happy that the value i derived was OK.
Now, that being said, after I posted the estimates above, i was thinking about it bit more and one of the things that can bias a magnitude estimate in a CCD image is the linearity of the pixels. I notice in my 5 minute image that the pixels of the supernova are almost at their limit, although not saturated, so I think i should go back to another image with a shorter exposure and compare the brightness results.
My estimate above was done quickly while I grabbed some lunch at work, so there's a good chance that I should have used an image with lower pixel levels so that the response is still well and truly linear.
I'll check further when i have more time and get back to this thread. :)

keep watching!

[Terry B]

Results from 4/11/12
These have been analysed using Vphot software and are an ensemble of about 6 comp stars. The error range is in the brackets.

B = 12.435(0.034)
V = 12.502(0.024)
R = 12.440(0.029)
I = 12.590(0.051)

The spectra is attached.

[Greg Bock]

Thanks for the post Terry. I'll trust your numbers more than mine :)
I'll go back to my image and see if I can also get the same figures too.

[Paul-SunCoast]

Awe inspiring. Thank you for sharing it. I'm a complete tyro but this is why I am so fascinated by the whole subject. Paul

[Paul-SunCoast]

I'm rapidly learning why these pages are so well used. The bar is set high and provides us beginners with astonishingly good advice and standards to achieve. If you'll excuse the lack of science here - beautiful.

[Greg Bock]

HI Paul, welcome to the whole new world of doing 'astronomy at the speed of social media!"

There is sooo much to learn and do compared to only a few years ago...good luck.

[lepton3]

Conditions are pretty poor here tonight, but I have got enough data to get an update on the brightness of this SN.

Don't know why, but my mag measurements seem to be consistently brighter than others I have seen published recently.

So I'm including a "raw" image, no curves applied (hence no pretty galaxy to view) just stretched the top and bottom levels to let you judge for yourselves.

Even by eye, seems to me it's brighter than the 12.2 star, dimmer than the 10.2 star. Do the photometry, and it comes out to 11.3!

I'll update this when I properly reduce the images, but it looks like this is the brightest SN of the year by some margin.

-Ivan

[Terry B]

What filter are you taking the image through?
Your image has a star labelled R=10.2 but the R mag for that star on the AAVSO comp stars is 11.247 and a V mag of 11.652.
Your other labelled star isn't in the AAVSO comp star lists so I can't check it. The star under it is though and measures V = 13.539 and R = 13.105
Use the VSP here http://www.aavso.org/vsp to create a chart. Just put SN 2012fr in the label field and select "E" chart size for a good CCD size image. You can then also create a photometry table for the comp stars.

There is lots of info here as well
http://cador.obs-hp.fr/sn_tarot/PSN_J03333599-3607377/
and here
http://www.astrosurf.com/aras/surveys/supernovae/sn2012fr/obs.htm
Cheers

Terry

[entity62]

Three snaps with the Mallincam video cam from tonight.

[Greg Bock]

Thanks for the tips Terry, lots to learn here...(now I just need the time to sit down long enough to study it all!)

[lepton3]

Thanks Terry, that explains it!

I'm using an Rc filter. So, with the AAVSO photometry sequence, I now measure the mag at 12.07.

-Ivan

[Greg Bock]

Hi guys,
I reviewed my magnitude estimates in my image of 5 November as suggested. I used a 30 second subframe and the AAVSO chart for that area as suggested by Terry, and now I get mag 12.5, not 13.1 to 13.4...seems to be more agreeable using that technique with a subframe where the pixels are still in a linear range.
thanks for the help guys.

[mithrandir]

Anyone imaging NGC1365 might catch 2012 VB5. This NEO will pass within 2 degrees (PA 255) at around 07:25 AEDT on the 9th. It might be still dark enough for the Perth guys (04:25 WST).

[rogerg]

My attempt tonight.

What a difference a night makes. Collimation and remembering to enable PEC which must have been off for months, and now finally my images are nice again.

Image details:
10 x 180sec
ST8 @ bin 2x2
FL approx 3090mm
f/10
12" Meade SCT on PME

[SkyViking]

Beautiful shot Roger! I was out taking images of this one last night. The SN seems very bright indeed, it's a beauty!
There seems to be a handful of clear nights ahead here, so hopefully I can get more data :D I got 4.5 hours so far, all luminance and no RGB yet.

[rogerg]

4.5 hours is significant data! I look forward to seeing your results :)

[Suzy]

I've been waiting for clear skies since last Sunday to have a go at this.
The SN in M95 earlier this year sat at mag 13 and I was able to "just" spot it using averted vision; it blinked in and out. That's thru light pollution, neighbours lights on and only a 10" dob- so there's hope for many people out there that want to give this one a go. ;)

A big thank you to everyone who is contributing images, mag. estimates and other info here- it's a huge help for me & others for sure.:thumbsup:

I only wish there were more visual people reporting on this here, it would help us visual observers a lot. Ron's observation of it thru his 8" was particularly helpful especially when it came to determining the brightness visually.
That little triangle asterism & a couple of other stars there looks a good guide- I have a feeling this is going to be one very dim galaxy to find from my location, so I need all the star guides I can get. Guys, some of those widefield shots showing a larger star field are a big help to us visual observers.

This is what I call visual observing at it's finest- a great challenge and a great thrill when spotted! Well, for me anyway, when electronic guidance will only take me so far & the rest is up to me. Ah, the thrill of the chase... :D

[Terry B]

Suzy
Go to the AAVSO VSP I mentioned earlier and make a finder chart that is suitable. Maybe a "B" size and change the mag to a level that you can see through your scope. ?mag 12.5 or so. Then the SN will be labelled on the chart and easier to find through the scope.

[Suzy]

Thanks Terry, I'll give it a go, but I find their site torture to navigate through, not sure how I'll go but I'll try- would be great if so!

Meanwhile what I have prepared and ready to go is a starry night map going as deep as I could go- grrr not that deep really :rolleyes:- plotting out the mag of some stars, then a pic of Ivan's (inverted) to go deeper.

125897

125898

The SN in m95 was at the limits of my scopes capabilities, so yes I would say nothing over mag.13 for me.

[Terry B]

Just use this direct link
http://www.aavso.org/vsp
Type SN 2012FR into the title and select B visual. Change the mag limit to 12 and it will print a good chart.

[Suzy]

Too easy. Done! :thumbsup:

Many, many thanks Terry, I appreciate it. :)

[SkyViking]

Here is a quick crop of what I got yesterday 7th November. No RGB data yet though. I was hoping it would stay clear tonight but no luck.

Exposure: L 42 x 5min, total 3hrs 30mins @ -30C
Telescope: 10" Serrurier Truss Newtonian f/5
Camera: QSI 683wsg with Lodestar guider
Filters: Astrodon LRGB E-Series Gen 2
Taken from my observatory in Auckland, New Zealand

[rogerg]

Excellent image :thumbsup: You have a flat undistorted field I yearn for :)

[rogerg]

I wonder what those in the know think of this magnitude estimate?

Camera is NABG, ST8.
Taken from a single reduced 3 minute exposure.
The rest is probably self evident from the screen shot.

Roger.

[SkyViking]

Thanks Roger, and that magnitude is certainly fascinating.
With NGC1365 being 56 million light years away I calculate an absolute magnitude of -18.87!
So if SN2012fr was in the place of say Betelgeuse, its apparent magnitude would be -12.39. More or less like the full Moon! :eyepop:

[rogerg]

That would be bright :)

I haven't been following closely, I think it is still increasing in bightness isn't it? (It's not just my 12.2 is an error?).

It sometimes takes me a while to catch on to these events, but I have now scripted it in my nightly script, so it will be interesting to graph the brightness over it's life span at the end.

Regards,
Roger.

[Terry B]

Roger
What filter if any was the image taken with?
I forget what database astrometrica uses for comp stars but it is different to the standard stars on the AAVSO site. These are probably better to use as they are reproducable betreen observers.
The aperture needs to be bigger. I usually use 3 or 4 x the fwhm as this gives more reproducable results.
Cheers
Terry

[rogerg]

Hi Terry,

In Astrometrica you can choose from the usual databases. At the moment I have it set to NOMAD, as the other option I did have it set to was UCAC3. For some reson my local UCAC2 wasn't working last night.

Could you clarify what you mean by bigger aperture? Are you suggesting it is better to estimate the magnitude from a stack of exposures? Not sure what you mean by using 3 or 4 x the FWHM sorry :)

[Terry B]

What I mean by bigger aperture is the size of the circle that the stars flux is measured. In your image there is clearly lots of the star flux outside the little circle. Your measured FWHM os 3.5arcsec so the circle needs to be 3 or 4 x this size. You will need to work out how many pixels this is as I don't know the resolution of your scope.
The UCAC3 databases are good but the accuracy depends on the filter being correct.
There is some advantage to averaging a few exposures to improve noise but you are probably better to measure individual exposures and average the results.
Any form of "stretching" of the exposure will make photometry measurements unreliable so just use plain dark and flat processed exposures. Flats are very important and must be used for accurate photometry.
cheers

Terry

[rogerg]

Ahh, thanks, I understand better now. I haven't noticed if that circle can have its diameter changed in Astrometrica.

I assumed it would calculate the magnitude based on the brightness of other stars in the image and then using the single brightest pixel value from the estimate star, I wonder why having more surrounding the star being included in the estimate has n impact? I should RTFM on the subject.

Flats, stretching, etc - have that covered.

Thanks,
Roger.

[lepton3]

I think Astrometrica doesn't use aperture photometry, it fits a point spread function (PSF) to the pixels.

-Ivan

[lepton3]

Here's my light curve so far. Last data point is for last night (8th Nov). Looks like it may be close to peaking.

-Ivan

[rogerg]

Very interesting, thanks for sharing, and thinking to record it from so early on!

[Terry B]

I only have 2 data points due to the crappy weather but here is the graph. It is from the AAVSO data.

[lepton3]

Got some more data last night. It is now at R-band Magnitude 11.97+/-0.02, and the curve is flattening off.

I guess it will probably peak tonight or tomorrow night.

-Ivan

P.S. I am maintaining the lightcurve on this page: https://sites.google.com/site/ivansastronomicalprojects/project-definition/sn-2012fr-photometry

[rogerg]

I had multiple complete equipment failure last night :( so no light magnitude estimate for me! :mad2:

[SkyViking]

I've just finished a high resolution image of NGC 1365 with SN2012fr, using the L data I got on the 7th plus 3 hours of RGB from 9th Nov. Attached is a downscaled version of the image (a thread with the full res image will be up soon, but right now I got to go to bed :))
It's quite spectacular how intensely blue the SN is!

[cometcatcher]

Wow, it sure is blue! Spectacular image.

[Suzy]

Outstanding pic Ivan! :eyepop:

I'm still waiting for our bad weather to clear up so I can take a look visually- just looking at the weather forecast, Wed & Thurs are looking good for Brisbane.
I need to catch this SN in in its peak- haven't much time by the looks of it.:prey:

[lepton3]

Another clear sky last night, so a chance to gather more photometry data on this SN.

On the 9th, it looked like it might have flattened out, but last night (10th) it was brighter, and still rising. R-band magnitude 11.90 +/- 0.03

For those wanting to view this visually (I'm thinking of you, Suzy), I've seen reports the SN is easily visible in a 10", but only the core of the galaxy is visible. With a goto scope, you are laughing. If you are manually pushing your Dob, I guess you need to be armed with dark skies and some charts.

Slightly embarrassed to say personally I have not been inclined to actually look through the 'sope -- then I'd have to take the flats again!

-Ivan

[Suzy]

Thanks Ivan :thumbsup:

Ron spotted it easily from his dark site thru an 8" and he seems to think it should remain bright for a couple of weeks, so that sound like it's back in keeping with what he said; I got worried eeeek when it looked like it was flattening out re your prev. post. If I nab it in in my 10" the next few days at it's peak, I'll be very happy.

I don't expect to see any arms from my light polluted site, just the core as you said. Which is what's going to make my job harder I think.
I have push-to-go (Argo Narvis), but with faint/small objects that can be just on the threshold of visibility, I find a star chart is useful so I know where to look harder in that area. A map showing a good deep starfield also helps to determine/confirm it's the SN in the right area and not just a faint star. And often the object can be put just out of field of the ep by the Argo- so sometimes hunting is involved, esp. if it's tiny & faint.

Go on Ivan! Do it! :D It should be quite a rewarding experience seeing this thru both means. Allow that eye to bathe in all those photos that took 56 million light years to hit your eyeball! It's a rush I tell you! :D

I've just learned that this galalxy is called "The Great Barred Spiral Galaxy" so that in itself is worthy of a look for me! :D

[SkyViking]

Thanks for the update Ivan. Impressive with a 11.90 magnitude! If that's in R then I assume B must be even brighter?

I've posted a much improved high resolution colour image here in this thread: http://www.iceinspace.com.au/forum/showthread.php?p=913773
This supernova just looks gorgeous.

[Glenpiper]

My latest low resolution spectra (below), taken last night (10 Nov) from urban Melbourne shows the strong 'blue' component ... fairly typical of a type 1a.

[Merlin66]

Bernard,
Very good spectrum! Well done!

[lepton3]

Bernard, thanks for posting the spectrum. Looks like good work.

From my reading, I understand the the strong emission in the blue end for type Ia at this point in its evolution is due to the decay of Nickel. This will be the case around peak brightness, as we are seeing the shell.

Weeks and months down the track, the shell will have expanded to transparency, and we will then see the core, which will be less blue.



I measured the R-band brightness again last night, it was 11.97 +/- 0.03 .. So possibly flat, possibly dimming. However there were thin clouds, so the accuracy can be affected. I think we will need another data point or two before deciding where the peak is.

I have only been measuring R so far, but I think Terry has measured other bands so may be able to give us a comparison.

-Ivan

[Terry B]

I took a spectra and photometry last night but haven't reduced them yet. It was very difficult as I had howling wind and even 20s exposures were very difficult. The spectra was fine though. If the star moves off the slit it just reduces the through put and doesn't give trailed images like the photometry images. Hopefully some of the exposures will be ok.

[Glenpiper]

Hi Ivan,

I've found various explanations for the type 1a process ... which is still not fully understood. One says that the decay of NiII, and higher Ni ions, results in heating the expanding shell to very high temperatures -> hence the very blue continuum of the SN remnant. Other sources say it is the decay of 56/27 Cobalt that is responsible.

Normally SN explosions destroy the progenitor star so it is unlikely there will be any core left to see, unlike PNs.

[mental4astro]

Ha! I pinned the bugger visually! And from home in Sydney.

Man that was hard work. 1365's core is so faint under Sydney's skies. The only way to see it using my 8" f/4 dob was to up the magnification as far as possible. Low power JUST showed a hint of the core. Upping the magnification to 100X was necessary to make out the SN which is brighter than the other foreground stars that accomany it close to 1365's core. Kevin's photo of the area helped me locate and confirm the sighting (http://www.iceinspace.com.au/forum/attachment_browse.php?a=125519).

And true to form, as soon as I was confident of the sighting, it clouded over and no chance of a sketch.

Now, if the clouds play ball and bugger off this Saturday...

Mental.

[cometcatcher]

Glad you found the widefield shot useful Alex. Would you believe I haven't actually seen the SN visually yet. I haven't been able to drag the 10 inch out and I can't see it in the 5 inch.

[mental4astro]

How rude I am! Yes, thank you for the shot too Kevin!!! :thumbsup:

Sometimes less is more, and I pegged this photo of yours in my mind for this very purpose.

[Glenpiper]

Hi Ivan,

>Normally SN explosions destroy the progenitor star so it is unlikely there will be any core left to see, unlike PNs.<

I forgot to qualify that statement with the comment that only type Ia SN leave no compact remnant. The other types (Ib,Ic,II) do end up with neutron star, pulsar or black hole cores.

[lepton3]

Good point Bernard. It seems the theory is that later stages of the lightcurve show emissions from material that used to be the core of the progenitor, now a rapidly expanding shell.

I measured the brightness again last night. It was brighter, at R-band mag 11.88 +/- 0.02 and still rising ever so slowly.

It's lucky to have had so many consecutive nightly sessions! The light curve is coming along nicely.

-Ivan

[Terry B]

Spectra from 11/11
Similar to Bernards.

https://gelato.tng.iac.es/plots/plot_80pc4e37jxet.png


Cheers
Terry

[pvelez]

That is just so totally excellent Terry!

Can't wait for the clouds to part - hopefully by the weekend.

I took some B, V and R images last night but have yet to reduce them. Will get the LISA onto this one soon.

Pete

[lepton3]

I took R, B and V photometry on the night of the 13th. Results were:

R = 11.878 +/- 0.020
V = 11.944 +/- 0.018
B = 12.177 +/- 0.028

Brightness seemed to be flat.

I also received a SA100 grating that day, and decided to try it out. My first attempt at a spectrum is attached.

I have roughly guessed the calibration for wavelength and detector sensitivity based on example spectra around, so this is hardly exact, but I think it shows the features you would expect for the Ia supernova.

I must say there is a lot to learn in this field.

-Ivan

[Glenpiper]

Hi Ivan,

Excellent progress with your new Star Analyser (SA100) ... now the serious work starts, learning how to process the raw spectral data! While there are a few free, and commercial, software programs that do this task I strongly recommend Buil's free ISIS. http://www.astrosurf.com/buil/isis/isis_en.htm. I've been using ISIS for a number of years and it is constanly improving. I believe Terry also uses it. You also need to subscribe to at least one of the serious (dedicated) spectroscopy groups. I can get you the links if needed.

[Glenpiper]

This Type Ia SN continues to evolve and the MgII, FeII, SII and SiII absorptions are even more prominent. My low res (R=580) spectra of 13 November:

[Terry B]

Very good Bernard.
I've had crappy weather. Thunderstorms last night that cleared too late for me to go out.

[Glenpiper]

Hi Ivan,

I'm puzzled by your B magniture being dimmer than the R and V. Given that we know, from spectra, visual and history that this SN has a very strong blue continuum I would have expected B<V<R, not the reverse.

> I took R, B and V photometry on the night of the 13th. Results were:
> R = 11.878 +/- 0.020
> V = 11.944 +/- 0.018
> B = 12.177 +/- 0.028

[Glenpiper]

Hi Terry,

I can nearly count on the fingers of my two hands the number of imaging nights I've had in the last few months ... I've just been lucky to have had a few of those in the last couple of weeks :(

[lepton3]

Hi Bernard,

I've double checked the images and reference magnitudes, and can't see any error.

Could this be due to the passbands of the Bessel filters? The R filter has a wide passband, and includes a fair bit of V and IR, whereas the B and V filters are quite a bit narrower.

-Ivan

[Terry B]

For what it is worth I took a single B exposure on 13th. It clouded over and I didn't get any other exposures with other filters.
The B measurement was 12.104 (0.04 error).
This is pretty close to your measurement.
I seem to be the only person that has entered their data on the AAVSO website. All these measurements need to be submitted.
Cheers

Terry

[Glenpiper]

Ivan, Terry,

This question of the B magnitude is worth investigating, given that for this SN we believe it is very 'blue', which should be evident in the BVR magnitudes. Alain Klotz, the discoverer and former amateur turned reputable pro, plots the BVR results at http://cador.obs-hp.fr/sn_tarot/PSN_J03333599-3607377/ (2.Observation Follow-up), which do show that while the B mag was fainter than the V in the early stages it is now brighter since the start of this month ... which is what I would expect.

Ivan, while your suggestions make sense (and I don't question your methodology) the end results, after full TC calibrations and extinction compensation, should result in correct BVR mags.

While I used to do only photometry, mainly CV stuff, I no longer have time for it since switching to spectrometry many moons ago, so I'm rusty in that area and obvious reasons for the B discrepancy don't readily spring to mind. Hopefully younger minds will fathom it out quicker than I can.
Cheers,

[pvelez]

I managed a few shots on 13 November - though I didn't manage to take flats so my data may be dodgy.

Oops - pilot error - I've now amended these results as I had failed to set up MPO Canopus to calculate using the correct filter.

My corrected results were:

B - 12.17
V - 12.06
R - 12.09
I - 12.50

When these damn clouds move on, I'll get the LISA onto this chap and will do this properly

Pete

[Glenpiper]

Pete's BVRI mags are going in the right direction ... becoming fainter into the red :)

[Terry B]

Data from last night (15/11/12)
I took 3 x 120 sec exposures through BVRI filters. These are then averaged and photometry performed using an ensemble of comp stars with VPhot software. Results are:

B = 12.139 err 0.042
V = 11.991 err 0.037
R = 12.027 err 0.032
I = 12.533 err 0.043

I also took a reasonable spectra at the same time. It fits a type 1a SN at 0 days very nicely.

[malclocke]

Finally nabbed it visually with my 10" Dob on the third attempt from reasonably light polluted Christchurch.

Was just about at Zenith, and managed to hop myself over from g and h Eridani. There was a comparatively bright galaxy there with 2 stars just visible near the core. I still wasn't really sure I was looking at N1365 so I jotted down the arrangement of the brighter stars on my notepad.

Thanks to Kevin's wide field shot I can confirm I was looking at the right thing, stoked to have bagged my first SN! Will try with more magnification if I get another shot at it to see if I can discern the SN itself a little better.

[MLParkinson]

Last Sunday night, I had the first clear, moonless night after weeks of cloud at my location in the southern suburbs of Sydney. I managed to capture a sequence of images of SN2012fr using my Televue 5 inch refractor and a luminosity filter. The unprocessed image at right suggests the supernova was brighter than the host galaxy on Sunday night (11th November 2012). My hunch is that the supernova must have been an easy visual target using a quality 85 mm refractor. This is because I have no trouble seeing NGC 1365 using my Televue 85 mm refractor at a reasonably dark sky location (obviously not the inner suburbs of Sydney).

SN2012fr in NGC 1365:

http://www.flickr.com/photos/mlparkinson/8191102271/

[Scorpius51]

The cloud partially cleared long enough for a quick look for SN2012fr in NGC 1365 tonight using a 10" Dob. The transparency was quite poor, but I was able to find 1365 with the use of charts generated by SkyTools (below). The sighting of 1365 was confirmed by the expected star patterns, but I couldn't clearly define the SN near the fuzzy core - but I was aware that something was there, though. I will need to wait for better viewing conditions to confirm it.

Cloud! :( Give us a break!

[Terry B]

The SN seems to be starting to decline in brightness.
Data from last night 18/11/12

mag:error:filter
12.252,0.041,B
12.081,0.034,V
12.111,0.026,R
12.579,0.055,I
See attached graph and spectra.

Cheers

Terry

[lepton3]

I agree Terry. By my measurements it peaked on Nov 13th UT.

-Ivan

[Glenpiper]

My weather over the last ten days or so has been the best this year, allowing me to get low-res (9.5A) spectra of this SN on four nights, one hour exposure each with a C11. I've attached a composite plot for the 10, 13, 18 and 19 November.

[pvelez]

Here's my results for this evening - yet to be calibrated fully so I'll let you know if they need adjustment when I am done:

B - 12.47
V - 12.20
R - 12.26
Ic - 12.75

I also realised this evening that I made an error with my last measurements. My corrected data for 13 November 2012 are as follows:

B - 12.17
V - 12.06
R - 12.09
Ic - 12.50

So I agree with the other gun photometrists - its fading.

Pete

[pvelez]

I should add - uncalibrated and mags calculated using MPO Canopus. All 180 second exposures.

Will have another go later in the week. I also need to properly calibrate with flats etc.

Still struggling to remember how to run these programs. Next week my sexing hand ST-10XME should be here. Should make it more interesting!

Pete

[MrB]

Sexing hand?!
:lol:

[Grahame]

for what its worth, here is my effort so far. 1.9 hours @ ~1850mm FL @ F7.5

this is totally uncalibrated data so im expecting the end result to be somewhat cleaner too

Cheers,
Grahame.

[MrB]

Nice one Grahame, look forward to seeing the final.

[pvelez]

Damn autocorrect on the iPad.

Second hand - d'oh!

Pete

[Glenpiper]

My spectra from earlier this evening (the red line) shows a brightning towards the blue end, so I would be interested to see if this is confirmed by BVR data.

[Terry B]

Bernard.
I took BVRI measurement (no spectra though) on Tuesday night.
It showed continuing decline in all colours.
http://www.aavso.org/tmp3/224577107.png

[pvelez]

Here's my latest data:

B - 12.83
V - 12.36
R - 12.44
Ic - 13.04

I'll plot this at some stage

Pete

[pvelez]

Does anyone have any more data on this?

Pete

[Terry B]

I've had cloud and thunderstorms every night for a week. Hopefully it clears soon.

[pvelez]

Same here - I collected some data on Sunday but I have yet to check it was ok. Otherwise its been decidedly ordinary

Pete

[pvelez]

Here's my data from 25 November 2012 - taken with my new ST-10XME:

B - 12.86
V - 12.60
R - 12.67
I - 13.26

This is calibrated.

It looks to me like the V, R and I are dropping but the B is diminishing at a slower rate.

I need to get my 13 year old son to teach me how to use Excel to plot this now.

Overcast in Sydney again - I expect no more clear skies till Friday now

Pete

[Terry B]

Interesting.
All I got last night was 1 x 5 min exposure of its spectra then the clouds rolled in. Too much noise in the image to be of any use though.

[lepton3]

Got another R-band measurement last night.

R = 12.59 +/- 0.03

It is dimming smoothly. Here's the latest plot.

127478

-Ivan

P.S. The light curve is being updated here (https://sites.google.com/site/ivansastronomicalprojects/project-definition/sn-2012fr-photometry).

[rogerg]

I'm after tips on graphing the brightness from my 11 observations over this SN.

Perhaps someone who's posting brightness measurements could advise?

Relevant software I have at my disposal:

Astrometrica
MPO Canopus
CCDSoft


I have tried with mixed success with these.

Astrometrica: I can process each image individually but the magnitude given seems to always be 12.0. Plate-solve is fiddly and manual for each image.

MPO: I'm getting index out of bounds errors and floating point errors. I will RTFM if this is the software I should be using...

CCDSoft: I have used the variable star function to attain a list of measured brightness values but don't fully understand the output.

Which should I have a more serious crack at getting accurate results from? Any tips?

Thanks,
Roger.

[pvelez]

Roger

I use MPO Canopus - but only to work out the mags without plotting. Will try that later in the weekend when I have time. Might be able to give some more value then

Pete

[pvelez]

My results from last night

B - 12.28
V - 12.81
R - 12.90
I - 13.31

I'll practice plotting and then see what I can produce

Pete

[MLParkinson]

I've looked at the price of MPO Canopus and it is well within my budget. Can you give me tips on buying a set of 1.25-inch BVIR filters? My hunch is this will be over $1000 so I will think long and hard before making the investment. Obviously the filters need to be of a very high quality. Thanks for the tips. Murray.

[Terry B]

Murray
I have used lots of different software for photometry. I have MPO canopus but don't use it for photometry as I find it somewhat difficult to use.
For most of my photometry I use AIP4WIN which comes with Richard Berry's book. You can buy it from here http://www.willbell.com/aip/index.htm for $99.
The comp star data just comes from the AAVSO database.
Another option is the free software Munuwin http://www.softpedia.com/progDownload/MuniWin-Download-156287.html
I have played with it and it is OK.
Photometry filters are quite expensive and are not available in Australia (AFAIK)
I have Astrodon filters and they cost US$175 each from Opt. They currently have "Custom Scientific" filters on special at US$150. I assume they would be fine. See here
http://www.optcorp.com/ProductList.aspx?uid=319-327-1157-863
Cheers
Terry

[Terry B]

Data from 28/11/12
13.066,0.046,B
12.684,0.048,V
12.766,0.026,R
13.224,0.057,I
It is slowly decreasing in brightness.
Spectra is attached for 28th and 30th.
http://www.aavso.org/tmp3/667637308.png

[Glenpiper]

Hi Terry,

I'm happy to see you are still getting spectra of this SN as I've switched my spectrograph back to a high-res mode for another project ... not that the weather is cooperating on that!

Custon Scientific cheaper than Astrodon ... that is a surprise, as CS used to be the more expensive and desirable of the two. I understand that the Schuler BVRIs (once the 'poor man's CS) have improved since Don, of Astrodon, took them over ... so have the tables been turned?

[Merlin66]

Murray, you have a PM

[Greg Bock]

Wow guys, it's refreshing to see so much activity around this SN event, and also to follow the emergence of the spectral and photometry data..keep it up!

[lepton3]

Fascinating to follow the evolution of this supernova. It is moving into a new phase, where the brightness is levelling off. Apparently this feature (I've seen it called the "shoulder" in articles) is commonly seen for type Ia supernovae in the R and longer wavelength bands.

-Ivan

P.S. For the person who was inquiring about filters, FWIW I use Custom Scientific photometric filters and have not had any reason to fault them optically. A minor niggle is that the thread is a bit small for my Orion 5-posn filter wheel. I pack the threads out with teflon tape to get them to sit snugly in the filter wheel.

[lepton3]

Maybe I have made an error, but tonight my measurement of this SN shows it has brightened by about 0.19 mag.

I've checked the images carefully, and the plate magnitude differs from that of December 5th by only 0.003 mag, so it really does look like it has flared.

On the 5th, it was 12.758 +/- 0.021, tonight (8th) it is 12.571 +/- 0.019.

I am measuring with an R filter. Can anyone confirm/refute?

-Ivan

[lepton3]

OK, tonight (9th Dec) the measurement is R=12.790 +/- 0.22, which is very nicely in line with the previous measurements, so for now I'm treating the data from last night as erroneous.

But I'm going to go over it again, because I can't see what was wrong with the setup.

-Ivan

[Glenpiper]

Alain Klotz, the pro who discovered this SN, has just posted the following to the Spectro-L forum:


Hello all,

The TAROT photometry continues and I seen that your
spectroscopic follow-up continues also:

http://www.astrosurf.com/aras/surveys/supernovae/sn2012fr/obs.htm

The maximum of B light is reached on the 2012 Nov.
11.0 (+/-0.5 day). The Delta_m15(B) = +0.77 which
is very slow decay. This last point is important
because it would mean a very large amount of Nickel
produced by the supernova.

Usually, a low value of Delta_m15(B) is correlated
to a high value of the brightness at the maximum
of light which is not the case for 2012fr.
The representative point of 2012fr in
this diagram is well outside the correlation.

So, the supernova begins to become atypic.
It should be a good idea to continue to observe it.
The present magnitudes today are:

B=13.7 V=12.8 R=12.7

The R and V magnitudes are now in the bump phase
which implies you can continue to record spectra
easily for one month more.

Clear skies,
Alain.


__._,_.___

[lepton3]

The supernova continues along its evolution. This light curve is becoming a long term project -- 53 days in and 23 observing sessions so far.

We seem to be past the shoulder phase and back on to the usual decline. Still plenty bright for accurate photometry, and probably still possible to get spectra for a while yet.

-Ivan

[Terry B]

A spectra form last night. It is still bright enough for me to obtain a spectra with 1 hr of exposure.
https://gelato.tng.iac.es/plots/plot_S6Ffnl7313J5.png

Terry

[LewisM]

Any new IMAGES? Haven't been able to even think about getting some shots of it for well over a month now, and wondering how it looks now?

[Terry B]

I took BVRI images at the same time. Ill upload them later
Terry

[Terry B]

Pics from last night. They were taken with a V filter.
The second one is labelled

[pvelez]

Terry

I have the LISA set up and ready to go this evening after the sun sets - what V mag do you have for this one?

Pete

[Terry B]

For SN2012fr
V= 14.113
R = 13.794 last night.
I used 600 sec exposures.
To position it on the slit I use 3 sec exposures with my STi guider and this showed it up well enough.

SN2012hr is a bit brighter.
It is V = 13.76
R = 13.74


Cheers
Terry

[pvelez]

Cheers Terry - I'm having a go at SN2012hr as I type. As you say, its a bit brighter.

Crossing my fingers - its a cheeky one to find among all those other stars.

Will post tomorrow on the Peter M's other post if I have any luck

Pete

[rogerg]

Here's my image from tonight. I now have observations from 22 nights over the SN's life. I'm still not confident I know what I'm doing with magnitude estimating to have bothered graphing them yet.

This is a screen shot from Astrometrica.

It's reported 14.4 is certainly fainter than the mag 12 it was giving me back at the start of my observations, suggesting I'm doing something right with the magnitude estimating.

Regards,
Roger.

[Andrew Pearce]

Hi All

This SN has faded a fair bit now. I visually observed it last night and made it mag 14.8 at Jan 2.57UT.

Regards
Andrew Pearce

[rogerg]

Here is my attempt at graphing my observations to date.

Open to comments/criticisms.

I used CCDSoft's "Generate Light Curves" functionality for "Stationary (variable star)". The magnitudes I specified for the two reference stars used were obtained from Astrometrica's values for the reference stars it identified in the image (I couldn't seem to find/click on the stars in TheSky to obtain magnitude that way).

The refernece stars are shown in the attached screen shot from CCDSoft.

Roger.

[Merlin66]

Roger,
Was the red circle shown on the SN, the measuring aperture for the magnitude??

[rogerg]

I don't know. There wasn't any obvious way to change the aperture if the aperture is relevant to the method of magnitude estimation CCDSoft uses. I'll see if I can find out any more about how it's done in CCDSoft.

[Merlin66]

In AstroArtV5 you can vary the aperture to suit the star size....
In photometry they recommend a measuring aperture x2 to x3 the FWHM size of the target star.....

[LewisM]

Thanks on the visual images guys.

[Terry B]

Excellent Roger
It is worth looking for reference star mags from VSP (http://www.aavso.org/vsp) on the AAVSO website. These will almost always be more accurate than TSXP or astrometrica.
The AAVSO has magnitudes for the star to the left on your image these are
B = 15.052
R = 14.295
I = 14.025
These mags have been taken from APASS data that is accurate to about 0.05 mag for mag 14 stars.
I have used the photometry tool with CCDSoft but only for a quick estimate. You don't seem to be able to vary the parameters. There are other aperture photometry programs available that are better. AIP4WIN is a very popular one and reasomably cheap.
Cheers
Terry

[rogerg]

Thanks Terry. Those mags are slightly different to what I was using for that star (14.7) but then I have been using the clear filter rather than BRI so at best I am going to get an approximation regardless.

Ken/Terry .... After doing quite a bit of searching and reading I'm reasonably confident of my understanding that: CCDSoft uses SExtractor. The parameters for it's use are configured via the Photometry Setup dialog which contains attributes for aperture, focal ratio, pixel size and seeing conditions. My understanding is these parameters would be sufficient for determinig appropriate aperture size. The indication to me is that it uses these values for configuring SExtractor for aperture photometry in the background, and that the circles shown around the stars on the image are simply to indicate star selection rather than aperture size. This leaves me with no reason to doubt the method used by CCDSoft even though CCDSoft doesn't seem particularly popular for this type of work (perhaps only because of it's lack of transparency regarding how it works?).

I have so many tools installed for different photometry/astrometry/etc it's easy for them to be lost amongst each other. Sometimes I find it easier to simply try with what I have rather than learn another. For estimating magnitude I've typically used astrometrica. I was tempted to use Astrometrica for this graph but thought CCDSoft would make it easier, as with Astrometrica I need to measure each image individually then manually put them in a table. I may move to something else but I wonder if AIP4Win the best? SExtractor seems to be a highly regarded choice by the pro's. Maxim has similar capabilities to CCDSoft (on the surface at least, I haven't dug in to it's inner workings). Similarly I have MPO Canopus which does light curve analysis too, but have little idea at this stage how it compares for the task.

Out of interest, attached is a result from Maxim.

[rogerg]

I've been playing with Maxim some more. It's photometry tool seems very easy to use and quite powerful, as well as having documentation.

I'm still learning ... particularly with regard to what aperture size and annulus size to use, but have a new plot. By changing the aperture down, the estimated mag is quite different, now 14.557 being the most recent reading from last night.