Nova Sagittarii No 4.

[bojan]

While playing with my modified Canon 200mm, It seems I managed to image this nova (see email from AAVSO, below)
at the same time as discoverers.. if not a bit earlier
This image (200% crop) was taken on Oct 26th, 9:05 UT.
The suspected Nova is in the centre..
Could someone check this please, it is cloudy here in Melbourne at the moment?

On the image i took on 19th (with 135mm lens) there is nothing there...



*********************************** *********************************
AAVSO Special Notice #173

NOVA SGR 2009 No. 4
October 26, 2009

Central Bureau for Astronomical Telegrams Electronic Telegram No. 1994 (Daniel W. E. Green, ed.) reports the discovery of an apparent nova by Koichi Nishiyama, Kurume, Fukuoka-ken, Japan, and Fujio Kabashima, Miyaki-cho, Saga-ken, Japan, at magnitude 9.3 on two 60-s unfiltered CCD frames taken on Oct. 26.439 and 26.440 UT. Five unfiltered CCD frames taken around Oct. 26.455 yielded mag 9.3 and the following position:

R.A. 18:31:32.79, Decl. -16:19:07.5 (equinox 2000.0).

Nothing is visible at this position on survey frames taken on Oct. 20.449 (limiting mag 13.9) and 21.451 (limiting mag 13.4). Following posting on the Central Bureau's unconfirmed-objects webpage, P. Corelli, Pagnacco, Italy, writes that his 10-s CCD frame taken on Oct. 26.764 yields mag 9.3 and position end figures 32.79s, 07.8"; he adds that nothing is visible at this position on a Palomar plate (limiting mag 21.0).

Finder charts may be plotted by entering the coordinates above into AAVSO VSP: http://www.aavso.org/observing/charts/vsp/

N SGR 2009#4 has been added to VSX and been assigned the identifier VSX J183132.7-161907 and the AUID 000-BJQ-768. Please report observations to the AAVSO International Database as N SGR 2009#4.

Good observing,

Elizabeth O. Waagen, AAVSO

[Rob_K]

Hi Bojan! Well done, that's certainly the nova! With all the cameras that are aimed at the sky these days, it's a wonder more pre-discovery images don't come to light (actually that's the problem I think, they don't come to light!). I snagged one last year, N Oph 2008 No 2, about three days before it was discovered, only of course I didn't know it was there till later!

I've attached your pic with the nova marked, for those who aren't quite sure which star it is, and a shot of mine taken a day later than yours (10:00, 27 Oct 09 UT). Clouds here too...

Cheers -

[bojan]

Thanks, Rob
Sorry for not marking it more clearly, I was in a hurry a bit but I knew that people who are interested in this sort of stuff will know how to look at that image.
It is interesting that its colour is pretty whitish, so I wasn't entirely sure is it or is it not
I expect it to redden significantly in the next days or weeks.

On your image it looks a bit brighter, lets do some photometry and compare the results

[bojan]

I estimated the visual mag (G-channel) was 9.83, based on comparison stars from Tycho catalogue.

The exact time image was taken is Oct 26.42045 UT, so it is only 26min 43sec prior to reported discovery... but still, I was there first

I have only one frame, it was taken during aiming the camera to M17.. it is not on the stack taken a bit later, of course.

[bojan]

Looks it is getting brighter since last time.. Later I will do a proper measurement, now I must hurry to work....

[jjjnettie (Jeanette)]

Pretty exciting isn't it.
If it's clear tonight I'll might have a look tonight.

[bojan]

Originally Posted by jjjnettie

Pretty exciting isn't it.
If it's clear tonight I'll might have a look tonight.

Yes it is.. especially because for this kind of work you really need only basic equipment.
This photo is 15x stack of 15sec exposures done with 200mm f/5.6, 400D set to ISO1600.

[bojan]

Yesterday (Oct 29th) Nova was 9.38, brighter by 0.5m since discovery.

[bojan]

Is anybody watching this?
It is still cloudy here.....

[jjjnettie (Jeanette)]

It's obscured by tree nebulas for me.

[bojan]

Well, what can you do..
According to http://www.skippysky.com.au/Australia/, it will be clear here tonight. I am wandering if it started to decline.
On last two occasions I had the opportunity for photometry, it was clearly brightening up :-)

[jjjnettie (Jeanette)]

They're predicting rain and storms over the next few days for us. We need the rain though so I'm not going to complain too much.

[bojan]

Same here :-)

[Terry B]

Originally Posted by bojan

Is anybody watching this?
It is still cloudy here.....

I took images on 1st and 3rd in BVRI. I have only processed the ones from the 1st.
B= 10.4
V=9.5
R=8.65
I=7.57

It sets behind trees for me at ~2030 so I won't be able to follow it for long.

[bojan]

Tonight it is 9.78 (visual)

[Terry B]

I've got storms tonight so can't measure it. On 3rd it had brightened compared to the 1st from V9.500 to 9.396.
It would be nice to know if it is still brightening. Maybe tomorrow night.

[DavidU (Dave)]

Very thorough work there Bojan.
At least we all know you were probably the first to see it.

[bojan]

Originally Posted by DavidU

Very thorough work there Bojan.
At least we all know you were probably the first to see it.

Thank you

However, it was only my camera seeing it first.. and it could not tell

[Rob_K]

Nice work Bojan! Any more obs? Seems to be dimming off slowly now.

Cheers -

[bojan]

It is 10.35 tonight.
Definitely in decline.
In couple of days it will be beyond reach of my current setup, so I will have to reduce the f number and increase exposure time to suppress LP and reach again.