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SN 2025rbs in NGC 7331

Deep Sky Galaxy Supernova NGC7331
Steven FanuttiSteveBen GodsonTiffsAndAstro
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Steven Fanutti avatar
Steven Fanutti avatar
As many of you might know, a supernova has been detected in the galaxy NGC 7331 in Pegasus. By coincidence, I was planning on observing this galaxy tonight to try out one of my custom finder charts. You can download and print it out for visual use. If you are observing with a large Dobsonian, you can print out the (B) chart and flip it upside down. Unfortunately, the supernova would be too faint for binoculars and small telescopes, but the galaxy is worth observing nonetheless. The (R) chart is for refractors with star diagonals.


NGC 7331 Finder Chart
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Christian Silk avatar
Christian Silk avatar
Good to know! I plan on imaging this in the coming weeks. Hopefully I can catch it and compare to my previous image of NGC7331.
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TiffsAndAstro avatar
TiffsAndAstro avatar
I imaged NGC 7331 badly about a month ago. Too soon?
Steven Fanutti avatar
Steven Fanutti avatar
An AstroBin user just imaged it. That's how I learned about it. The image shows the supernova near its core.
Steven Fanutti avatar
Steven Fanutti avatar
TiffsAndAstro:
I imaged NGC 7331 badly about a month ago. Too soon?


Another AstroBin user imaged the supernova near its core.
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Alan Brunelle avatar
Alan Brunelle avatar
Steven Fanutti:
TiffsAndAstro:
I imaged NGC 7331 badly about a month ago. Too soon?


Another AstroBin user imaged the supernova near its core.

Do you recall who imaged it?  If so, can you provide a link to the image?
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Steven Fanutti avatar
Steven Fanutti avatar
Alan Brunelle:
Steven Fanutti:
TiffsAndAstro:
I imaged NGC 7331 badly about a month ago. Too soon?


Another AstroBin user imaged the supernova near its core.

Do you recall who imaged it?  If so, can you provide a link to the image?

https://www.astrobin.com/x09y9r/
Alan Brunelle avatar
Alan Brunelle avatar
Steven Fanutti:
Alan Brunelle:
Steven Fanutti:
TiffsAndAstro:
I imaged NGC 7331 badly about a month ago. Too soon?


Another AstroBin user imaged the supernova near its core.

Do you recall who imaged it?  If so, can you provide a link to the image?

https://www.astrobin.com/x09y9r/

Thanks Steven!
TiffsAndAstro avatar
TiffsAndAstro avatar
Steven Fanutti:
Alan Brunelle:
Steven Fanutti:
TiffsAndAstro:
I imaged NGC 7331 badly about a month ago. Too soon?


Another AstroBin user imaged the supernova near its core.

Do you recall who imaged it?  If so, can you provide a link to the image?

https://www.astrobin.com/x09y9r/


Pretty sure it's not in my image from 10 days ago, but might go reprocess it just in case  

Thanks for the link
GalacticRAVE avatar
GalacticRAVE avatar
Well, the weather at my site was quite fluctuating the last week, thunderstorms and rain showers during the day, relatively clear sunsets to get the hopes high, and cloud fields during the night, got between 0.5 h and 4 h (of the max 4 h) of useable data per night. Read about SN2025rbs yesterday and put in on my schedule for the night, cloud forecast was very good, and at the end the conditions were similar to the last days - really challenging the patience of the astrophotographer. So, at the end of the night  I got 3min (sic!) of data, ie 1 frame on my EDGE11, but  enough to get SN2025rbs, which meanwhile is fairly bright and clearly visible near the center of NGC7331.
Steven Fanutti avatar
Steven Fanutti avatar
Well, the weather at my site was quite fluctuating the last week, thunderstorms and rain showers during the day, relatively clear sunsets to get the hopes high, and cloud fields during the night, got between 0.5 h and 4 h (of the max 4 h) of useable data per night. Read about SN2025rbs yesterday and put in on my schedule for the night, cloud forecast was very good, and at the end the conditions were similar to the last days - really challenging the patience of the astrophotographer. So, at the end of the night  I got 3min (sic!) of data, ie 1 frame on my EDGE11, but  enough to get SN2025rbs, which meanwhile is fairly bright and clearly visible near the center of NGC7331.

Well done! I hope your results will encourage others to try to capture it. I don't have the equipment to capture it, but I got lucky a decade ago with another supernova.


M81 and M82 with Supernova SN 2014J
Ben Godson avatar
Ben Godson avatar
Well, the weather at my site was quite fluctuating the last week, thunderstorms and rain showers during the day, relatively clear sunsets to get the hopes high, and cloud fields during the night, got between 0.5 h and 4 h (of the max 4 h) of useable data per night. Read about SN2025rbs yesterday and put in on my schedule for the night, cloud forecast was very good, and at the end the conditions were similar to the last days - really challenging the patience of the astrophotographer. So, at the end of the night  I got 3min (sic!) of data, ie 1 frame on my EDGE11, but  enough to get SN2025rbs, which meanwhile is fairly bright and clearly visible near the center of NGC7331.

Great image! It should continue to get a bit brighter as well, based on the distance of NGC7331 and the fact that it's a type Ia supernova. I hoped this supernova would get some interest from astrophotographers but was a bit worried by how close it is to the nucleus of the galaxy, you can barely see it at all in the discovery image, but it looks very nice here
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GalacticRAVE avatar
GalacticRAVE avatar
Last night I was more lucky and could get ~2h of data.

https://app.astrobin.com/i/pnplmb
Joel Lee avatar
Joel Lee avatar
Thanks for the notice about the supernova! I was wondering what to image on a local trip and this thread inspired me to go after this supernova. I got lucky and managed to get the supernova in this image here on Friday July 18, 2025! The integration is rather low but processing brought it out quite distinctly. I can't tell if the supernova is supposed to be bluish though since my system has some chromatic aberration (darn reducer). On autostretch, the supernova is fairly obvious on images where the core is rather dim. Ironically that was in the RGB filters while on L autostretch it was kinda difficult to see.



SN2025rbs in NGC 7331
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Steven Fanutti avatar
Steven Fanutti avatar
I'm glad to see other AstroBin users posting images of this supernova! 😊 I field tested my NGC 7331 finder chart at a dark site and it turns out that my chart has stars plotted much fainter than even my 12x80 binoculars were able to show me. Using the Aladin Sky Atlas, I estimate that the faintest stars plotted are around magnitude +12.5 to +13.0. I am able to see stars down to about magnitude +11.5 with my 12x80's. Unfortunately, however I did not positively see the galaxy. The last time I saw NGC 7331 visually was in the late 1990's using a 6-inch telescope with a ~50x eyepiece, although I should have technically seen it at visual magnitude +10.4 with my binoculars. Based on my observing experience, I would say that at 12x, the contrast was too low for me to discern the galaxy. On the other hand, the views of M51 and M101 were outstanding as those galaxies really stand out of the black sky at low power.

Has anyone attempted to view this supernova visually? If so, what equipment did you use? Based on what I have read about this supernova, I think that at least a 10-inch or 12-inch telescope would be required to spot it visually.
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Rick Krejci avatar
Rick Krejci avatar
I was able to get it last night...very bright still!





NGC733, Deer Lick group & Stephan's Quintet with special guest star SN 2025rbs
Steven Fanutti avatar
Steven Fanutti avatar
Rick Krejci:
I was able to get it last night...very bright still!


The latest AAVSO observations are around 12th magnitude. If anyone wants to try a visual sighting, now is the time!
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Steven Fanutti avatar
Steven Fanutti avatar
The supernova in NGC 7331 inspired me to post these images of SN 2014J. Check out the animation:



SN 2014J Composite



SN 2014J Animation
TiffsAndAstro avatar
TiffsAndAstro avatar
Have my pro version ;)

Steve avatar
Steve avatar
Here's a couple of hours from last night.  I think it might be fading a little now.  The blue color is expected, I believe.

Steve avatar
Steve avatar
I estimate a visual magnitude of about 15, which would be an absolute magnitude of about -15.5.  Type Ia peaks around -19.3, if Wikipedia can be believed.  So it’s fading away now.
Ben Godson avatar
Ben Godson avatar
Steve:
I estimate a visual magnitude of about 15, which would be an absolute magnitude of about -15.5.  Type Ia peaks around -19.3, if Wikipedia can be believed.  So it’s fading away now.

Are you sure about that magnitude? It would be a very very fast decline rate for a type Ia supernova which is typically only around 1-2 mags 15 days after peak.
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Ben Godson avatar
Ben Godson avatar
Very blue compared to the galactic nucleus (and most stars in the field too!)

Supernova 2025rbs and NGC 7331
Steve avatar
Steve avatar
Ben Godson:
Steve:
I estimate a visual magnitude of about 15, which would be an absolute magnitude of about -15.5.  Type Ia peaks around -19.3, if Wikipedia can be believed.  So it’s fading away now.

Are you sure about that magnitude? It would be a very very fast decline rate for a type Ia supernova which is typically only around 1-2 mags 15 days after peak.

Not sure at all!  I just eyeballed a 30 second sub and compared against a field star.   To me it looked about the same as GPM 339.285015+34.436674, magnitude 15.4.  Looks about the same in your image, I think.
Steven Fanutti avatar
Steven Fanutti avatar
Steve:
Ben Godson:
Steve:
I estimate a visual magnitude of about 15, which would be an absolute magnitude of about -15.5.  Type Ia peaks around -19.3, if Wikipedia can be believed.  So it’s fading away now.

Are you sure about that magnitude? It would be a very very fast decline rate for a type Ia supernova which is typically only around 1-2 mags 15 days after peak.

Not sure at all!  I just eyeballed a 30 second sub and compared against a field star.   To me it looked about the same as GPM 339.285015+34.436674, magnitude 15.4.  Looks about the same in your image, I think.

I tried myself to determine the visual magnitude using Aladin / SIMBAD. AAVSO observers are currently reporting visual magnitudes around 12. I would recommend using their Variable Star Plotter and taking a visual look to check the closest matching star that you could see. Then check that star with Aladin / SIMBAD. The V-magnitude is the number that you are looking for. I learned after creating my own variable star charts that right-clicking on Aladin gives you the B-magnitude instead. So, my variable star charts have B-magnitudes on them.  That's not a big deal as variable estimates can be calibrated to V-magnitudes later. The point is, make sure your estimates are in reference to V-magnitudes.
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