IC4901 supernova discovered by Greg Bock

gregbradley · #1 22-10-2011, 09:13 AM

I read the post by Greg Bock about discovering this supernova so I thought I would image it last night. It looked a bit small in the image using the Proline 16803 so I used the Microline 8300.

Apart from the usual dramas when you change over gear I got a couple of hours of it.

Luminance turned out best, rgb not so great yet. It would need quite a few hours.

Here is the luminance.

The Supernova is the bright star near the core. I don't know how to put those little marking lines in the image to highlight it.

7 x 10 minutes 2x2 luminance -35C CDK17/ML8300

http://www.pbase.com/image/139036871

Its quite a pretty galaxy and worth imaging in colour with lots of hours.
There must be lots of these "obscure" not imaged often galaxies in the southern hemipshere. I'd love a list of these.

Greg.

madbadgalaxyman (Robert) · #2 22-10-2011, 02:33 PM

Yes, Pavo and Indus and Telescopium are full of 12th to 13th Blue magnitude galaxies for which the best available images are only Digitized Sky Survey images!
Many of these galaxies are in the IC catalog, and a few of them are brightish non-NGC/IC objects with ESO designations.
This region of sky is very poorly known.....many of the IC galaxies have had no detailed study by professional astronomers!

I had better not promise to make an observing list of these galaxies, as I am notorious for "never getting A Round Tuit"

iceman (Mike) · #3 24-10-2011, 05:25 AM

Nicely done, Greg!

iceman (Mike) · #4 24-10-2011, 06:34 AM

This SN discovery by Greg Bock is such a great story, your image is timely and relevant. It's now IOTW.

PS: I rotated your image 180deg and put the markers on to identify the SN. I hope you don't mind.

PPS: Use the "Line Tool".

gregbradley · #5 24-10-2011, 07:44 AM

Wow, thanks Mike.

I'll check out the line tool.

Greg.

Terry B · #6 24-10-2011, 09:44 AM

Very good Greg.
I prefer the less imaged stuff and I agree it would make a good project for longer exposures.

gregbradley · #7 24-10-2011, 12:37 PM

If its clear tonight I think I'll add to it. Its actually quite a pretty galaxy.

I am not sure if Comet Garradd is still viewable in the southern hemisphere but it seems
to be quite pretty also at the moment with 2 tails in a V shape.

Greg.

Greg Bock (Greg Bock) · #8 24-10-2011, 12:52 PM

HI guys
thanks Greg for the image of IC4901 with SN2011gv for this post, I have had a very busy (domestic) weekend, so I haven't kept up with the threads and posts about SN 2011gv myself. It looks great.
I took a bunch of images of it myself on Saturday night between clouds for the purpose of measuring its brightness. I'll try to post the result as soon as I can but the conditions weren't very good here.

Greg Bock (Greg Bock) · #9 24-10-2011, 12:59 PM

HI Mike S,
as usual, there is also a back-story to this discovery which involves lots of good luck for change. I haven't detailed it yet, but suffice to say that I almost deleted the discovery image of IC4901 on the night of imaging due to software issues, but I took a moment instead to look at it more closely before I did delete it, and needless to say, almost fell off my chair when I spotted the new interloper.

Thanks for publishing Greg Bradley's image of it for IOTW too.

strongmanmike (Michael) · #10 24-10-2011, 03:16 PM

Hey Greg B, there looks like there might be a very faint outer section of spiral arms that would be good to try and reveal too

Mike

multiweb (Marc) · #11 24-10-2011, 05:37 PM

Good catch and a nice galaxy too.

atalas · #12 24-10-2011, 07:26 PM

Congrats Greg & Greg!

gregbradley · #13 24-10-2011, 07:32 PM

Quote:

Originally Posted by strongmanmike

Hey Greg B, there looks like there might be a very faint outer section of spiral arms that would be good to try and reveal too

Mike

Yes its quite a pretty galaxy. Its interesting how many of these galaxies there are in that close southern circle around Eta C and in and also there are lots of galaxies around NGC253.

Quote:

Originally Posted by Greg Bock

HI Mike S,
as usual, there is also a back-story to this discovery which involves lots of good luck for change. I haven't detailed it yet, but suffice to say that I almost deleted the discovery image of IC4901 on the night of imaging due to software issues, but I took a moment instead to look at it more closely before I did delete it, and needless to say, almost fell off my chair when I spotted the new interloper.

Thanks for publishing Greg Bradley's image of it for IOTW too.

Glad to help Greg.

Quote:

Originally Posted by multiweb

Good catch and a nice galaxy too.

Cheers. It's really Greg Bock not so much me. I just suffered through the hardware issues of changing over a camera. I know what you mean Greg about nearly deleting the image. I almost didn't take the shot because the Microline needed another adapter to work and then the focuser nearly got stuck - you get the idea!

Quote:

Originally Posted by atalas

Congrats Greg & Greg!

Cheers Louie.

mozzie (Peter) · #14 24-10-2011, 08:48 PM

great find greg......
been looking at it for the past hour and am pretty shore i can see it visually although withsome averted vision,quiet faint but a nice challenge..

Ross G · #15 24-10-2011, 09:54 PM

Hi Greg,

What an amazing capture.

A great IOTW.

Congratulations Greg Bock on your incredible discovery.

Thanks.

Ross.

mozzie (Peter) · #16 25-10-2011, 06:18 AM

stayed with the galaxy till around 10pm was able to see galaxy easily and there was many stars to see..as other posts above was looking towards the centre and was able to see faint stars and am shore one of them was the s/n..
thanks for the thread enjoyed the hunt last night...

gregbradley · #17 25-10-2011, 06:00 PM

Quote:

Originally Posted by mozzie

great find greg......
been looking at it for the past hour and am pretty shore i can see it visually although withsome averted vision,quiet faint but a nice challenge..

Greg Bock worked hard to discover this one.

Quote:

Originally Posted by Ross G

Hi Greg,

What an amazing capture.

A great IOTW.

Congratulations Greg Bock on your incredible discovery.

Thanks.

Ross.

Cheers Ross. Its really Greg Bock's hard work I was only trying to back him up as I had some clear skies that night.

Quote:

Originally Posted by mozzie

stayed with the galaxy till around 10pm was able to see galaxy easily and there was many stars to see..as other posts above was looking towards the centre and was able to see faint stars and am shore one of them was the s/n..
thanks for the thread enjoyed the hunt last night...

I'd like to see it visually. It is really quite bright. Obviously you need a library of images of galaxies to detect these as to me it looked
like a foreground Milky Way star and I would not have suspected it unless it were a galaxy I was familiar with. So those years of hard work Greg Bock has put in imaging galaxies to form a reference library for comparison really paying off now.

Greg.

Greg Bock (Greg Bock) · #18 26-10-2011, 01:33 AM

The weather here has really been a problem since discovery, almost no opportunity to image it.

Thanks for the reports guys. If you are looking visually for it, try printing one of the images from Greg Bradley or myself as a finder chart. (or use a red screen over your laptop display)

Bob Evans reported to me that he couldn't see it in his 12" scope the night after discovery, so it will be interesting to hear of any other visual sightings.

In the meantime, I am waiting for clear skies....please!!!!

rogerg (Roger) · #19 26-10-2011, 01:22 PM

Nice pic! and another discovery for BOSS! congrats! I had no idea, I have been consumed by work and not following IIS. Wish I could take a shot of it, but it's just been cloud cloud cloud here.

Greg Bock (Greg Bock) · #20 26-10-2011, 06:19 PM

OK guys,
so, here is the back-story summary. As you can see, it was a very lucky find for me because:
1. The galaxy is only high enough above the trees and house for about 1 hour per night between rising and setting
2. We had lot of broken cloud that night, so many of my images were cloud affected,
3. I wasn’t using my normal camera as it is in the US being repaired
4. I wasn’t running my normal search program. Instead, I was running a test program in an effort to try to isolate an on-going software problem that I have had for months that is stopping me from using it more effectively,
5. The supernova was in the third image of about 50 for the night of which only the first 15 were OK, the others were no good due to my software problem and I deleted them
6. Just before deleting the remaining 15, I glanced through them as a quick check to see if anything was obvious, and the bright object near IC4901 caught my eye
7. After I checked for asteroids and any previous discovery announcements for the new object, I texted BOSS members, and Peter was only just able to take a confirming image of it 20 degrees above the horizon. It set too low for him not long after he obtained that image.
8. After the discovery, it has been mostly cloudy, so if I didn’t find it on the night, I was probably never going to find it.

So, talk about “count your lucky stars!”..whew….