287 replies to this topic

[Dave Mitsky]

Yesterday's colorful setting Sun did not bode well for a chance to successfully observe supernova SN 2023ixf visually.  When my wife and I arrived at the Astronomical Society of Harrisburg's Naylor Observatory last night, the smoke was the worse than I've seen it so far this year.  Second magnitude stars were visible in parts of the sky but the transparency in general was very poor indeed.

 

However, a fellow ASH member was imaging M101 and I was able to see the supernova on the computer monitor of the ASH 10" imaging telescope.  Another ASH member and I attempted to observe SN 2023ixf using one of the observatory's 14" Meade LX200 SCTs.  M51 was barely visible due to the smoke.  M101 was essentially invisible but we may have seen the supernova.

I've included an iPhone shot that I took of the monitor screen.

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[Lan¡akea]

I observed the supernova both yesterday at 11pm UTC and today at 9pm UTC using a 12''f/5 with magnifications of 50-400x. Yesterday, I estimated the brightness as 12.0+/-0.5mag, today it brightened to 11.0+/-0.5mag. Certainly the brightest supernova I've seen so far. Also the earliest with less than 3 days after explosion.

The supernova could be approaching its maximum. Today, at 10:30pm UTC, the brightness is 10.6+/-0.3mag. I used a lot of reference stars so I am pretty confident in that value.

[astrotakis]

I managed to photograph the supernova (this Saturday 2AM, UK) using a Takahashi FSQ85-EDP with an Astrodon L Filter on an ASI 1600. 8 x 180s guided on an EM-400 2M.

 

 

Edited by astrotakis, 22 May 2023 - 06:25 PM.

[robin_astro]

ATEL 16046 gives B-V +0.2 

 In that ATel B-V = -0.2   (11.2-11.4)

 

2023-05-21T22:11:51.952 | 11.2 | 0.1 | B | 954
2023-05-21T22:13:14.311 | 11.4 | 0.1 | V | 954

 

https://www.astronom...org/?read=16046

 

 

Based on the spectra I believe it has been changing rapidly though (becoming bluer)

My spectrum from last night (taken close to the time of the photometry in ATel 16046) is significantly bluer than the confirming spectrum in TNS.  The continuum in my spectrum best matches an 18000K black body

https://britastro.or...81642b90b339b4b

 

Robin

Edited by robin_astro, 22 May 2023 - 08:15 PM.

[yuzameh]

 In that ATel B-V = -0.2   (11.2-11.4)

 

2023-05-21T22:11:51.952 | 11.2 | 0.1 | B | 954
2023-05-21T22:13:14.311 | 11.4 | 0.1 | V | 954

 

https://www.astronom...org/?read=16046

 

 

Based on the spectra I believe it has been changing rapidly though (becoming bluer)

My spectrum from last night (taken close to the time of the photometry in ATel 16046) is significantly bluer than the confirming spectrum in TNS.  The continuum in my spectrum best matches an 18000K black body

https://britastro.or...81642b90b339b4b

 

Robin

oops, got 'em muddled again.  I originally read the previous atel which was tricky to follow, and not the correction with the fixed table, so messed up.

 

Thanks

 

That's really hot then!

 

The V-R don't seem so weird now.

Edited by yuzameh, 22 May 2023 - 08:38 PM.

[Redbetter]

Thanks! That means a lot since after I uploaded my observation to the AAVSO, another person uploaded theirs and placed the supernova nearly a full magnitude fainter just half an hour before my observation. I know what I saw, just don't know what they saw...

 

So, are you saying that you felt the supernova was magnitude +12.2 on Saturday evening when you looked at it? And on Sunday evening you felt the supernova was magnitude +11.2? Interesting how your estimates are always about 0.3 fainter than mine. Well, at least we're consistent!

 

Any way around this? Assuming the SN is more like +0.3 B-V (blue in photographs it seems), I would normally think I need to keep the comparison stars just as close.

 

Scott H.

I estimated 11.1 last night, 12.2 the night before.    Your estimates for this one have been on the bright side of the visual range from what I saw in AAVSO and the photometric measurements, but different observers see these things differently and that is why they want multiple observers.  I can't check this now as AAVSO can't be reached. 

 

With respect to smoke dimming.  The only way I can see around it is getting away from the smoke, not taking measurements when there is any substantial amount of smoke.  As Robin notes, this is a very hot source, so the B-V is negative (e.g. -0.2).  The comparison stars have primarily been in the +0.5 range. 

 

I don't have a good feel for how much relative shift there might be for different stars with different levels of smoke dimming, but the absorption is stronger in the blue.  Smoke opacity tends to vary throughout a session, sometimes by several magnitudes, so it would be tough to come up with a scale for this, especially since the SN and stars have their own differing characteristic emission curves.  I can say that wildfire smoke made an excellent red filter for Mars.  

[Redbetter]

The supernova could be approaching its maximum. Today, at 10:30pm UTC, the brightness is 10.6+/-0.3mag. I used a lot of reference stars so I am pretty confident in that value.

 

Hard to say how bright it will become until we see it flatten out.  If it is a IIn as Robin's spectral results suggest, and if the redshift is 0.000804 or similar then it could reach the low 9's.  However, other information I am seeing for M101 suggests this nearby galaxy is further away than that--not surprising considering that this is such a low redshift, so local spacial velocities can be the same magnitude as the redshift.  I have seen estimates of 21 to 27 million light years.  That would put it in the mid 10's at peak.

Edited by Redbetter, 22 May 2023 - 09:43 PM.

[Raul Leon]

Hi, I observed SN 2023ixf on 5/20/2023: It was estimated at being 12th magnitude. I used a 17mm Ethos at 133x with my 14.5 Starstructure f/4.3, attached is my sketch.

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[Tom Laskowski]

I just saw it using my 5" Mak from my light polluted backyard. The sky conditions are not good but the smoke is not too bad tonight. It really helps having the supernova very close to the zenith. If it's clear tomorrow I'll go to my dark site 35 miles south of here.

[BKSo]

I observed the supernova last night with my 4" Meade 2045 at a Bortle 7 site. The sky was clear. NELM 4.0-4.5. M101 was not visible but the supernova was just visible with direct vision and easy with averted vision. The hardest part was making sure it was not other stars (the faintest star detected was about mag 12). The observation was consistent with a brightness of mag 11.

[sunrick]

My friend Tony in the Bluegrass Amateur Astronomy Club (Kentucky) just happened to image M101 on May 18th with a 12.5-inch telescope.  The skies were not great that night with some Canadian wildfire smoke.

 

For the first May 18th image, the time stamps on the RGB subframes ranged from 04:20:06 UTC to 06:13:34 UTC.  I don't see any sign of the supernova.

 

For the second image.....he recorded it May 22 when I told him about the supernova!  The May 22 image is from the early hours of May 22 UTC.

 

I attached his May 18th image first and his May 22 image showing the supernova second.  

 

Has their been a later image than this that did not show the supernova?  Could this have any scientific value?

 

Rick

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[SNH]

My friend Tony in the Bluegrass Amateur Astronomy Club (Kentucky) just happened to image M101 on May 18th with a 12.5-inch telescope.  The skies were not great that night with some Canadian wildfire smoke.

 

For the first May 18th image, the time stamps on the RGB subframes ranged from 04:20:06 UTC to 06:13:34 UTC.  I don't see any sign of the supernova.

 

For the second image.....he recorded it May 22 when I told him about the supernova!  The May 22 image is from the early hours of May 22 UTC.

 

I attached his May 18th image first and his May 22 image showing the supernova second.  

 

Has their been a later image than this that did not show the supernova?  Could this have any scientific value?

 

Rick

Send it to Dave Bishop since he is asking for such images on this webpage.

 

Just got back inside. Placed it at +11.0 Had to use the +11.1 far to the NW. The star I had used last night I have now found out had way too high a B-V. And I could see tonight that it was throwing me off.

 

Scott H.

[Procyon Lotor]

Just got back in from observing this and a few other things at a Bortle 5 site. Using comparison stars on an AAVSO chart, I estimate the supernova was about mag 10.8 - it was slightly dimmer than a star at the east end of a chain of 4 stars north of the galaxy with magnitudes 8.0, 11.2, 10.3 and 10.5, and significantly brighter than the mag 11.9 and 12.3 stars immediately to the east, but dimmer than the 10.3 star further east. 

[Dave Mitsky]

Yesterday's APOD is apparently causing some controversy.

https://apod.nasa.go...d/ap230522.html

[robin_astro]

My friend Tony in the Bluegrass Amateur Astronomy Club (Kentucky) just happened to image M101 on May 18th with a 12.5-inch telescope.  The skies were not great that night with some Canadian wildfire smoke.

 

For the first May 18th image, the time stamps on the RGB subframes ranged from 04:20:06 UTC to 06:13:34 UTC.  I don't see any sign of the supernova.

 

For the second image.....he recorded it May 22 when I told him about the supernova!  The May 22 image is from the early hours of May 22 UTC.

 

I attached his May 18th image first and his May 22 image showing the supernova second.  

 

Has their been a later image than this that did not show the supernova?  Could this have any scientific value?

 

Rick

Hi Rick,

 

Yes there have now been some later non detections. This AstroNote on TNS details the current situation on narrowing down the time of the explosion.  

 

https://www.wis-tns....ronote/2023-133

 

All early images are potentially valuable though as they help define the light curve so David Bishop's repository would be a good place to register them

 

Cheers

Robin

[robin_astro]

Yesterday's APOD is apparently causing some controversy.

https://apod.nasa.go...d/ap230522.html

Are ZTF claiming a detection 2 days earlier? I have not seen that reported. Is that the controversy?  (The problem is APOD only give general or third hand references which is pretty poor practise IMO).   As far as I am aware so far the earliest detection is  only  ~20 hours pre discovery and there are non detections to mag 20/21  to within ~26 hours of discovery (from amateur images studied by professionals)

 

https://www.wis-tns....ronote/2023-133

Edited by robin_astro, 23 May 2023 - 05:17 AM.

[Gil V]

There's a supernova in M101, and I'm out of town for work without a telescope for weeks. Sad.

Try a local library.

[Redbetter]

I estimated it at 11.0 tonight in dark skies (~21.2 mpsas, clear) with both the ST80 at 44x and the 20" at 156x.  It seemed a smidge brighter than last night, but not much more.  If I waffled on my step sizes, giving another half step on the bright side (which was considered), it would work out to 10.9, but no brighter for me.  It might very well have peaked, which would give some indication of the distance of M101, particularly when the 2011 Type Ia there is considered. 

[Dave Mitsky]

Are ZTF claiming a detection 2 days earlier? I have not seen that reported. Is that the controversy?  (The problem is APOD only give general or third hand references which is pretty poor practise IMO).   As far as I am aware so far the earliest detection is  only  ~20 hours pre discovery and there are non detections to mag 20/21  to within ~26 hours of discovery (from amateur images studied by professionals)

 

https://www.wis-tns....ronote/2023-133

Apparently, the supernova was stamped in on the April 20th image. The level of noise is the same in both images, which is very unlikely.

[Vedran]

Last night around 20:30 UT I've estimated SN2023ixf to be m=11.06 from Bortle 7 skies. I've used 102/500 refractor.

SN was quite prominent, but M101 was barely visible due to the LP and high humidity wich resulted in hazy skies.

[dhkaiser]

Last night around 20:30 UT I've estimated SN2023ixf to be m=11.06 from Bortle 7 skies. I've used 102/500 refractor.

SN was quite prominent, but M101 was barely visible due to the LP and high humidity wich resulted in hazy skies.

Your estimating to .01 magnitude?

[starbob1]

I observed m101 with my 15in last night 4.5 bortle sky' transparency was average' no smoke last night finally. The SN was easy to see but m101 was its usally faint smudge' but made seeing the SN a must' I'am in southern IN.  It was fun to see. 

[Vedran]

Your estimating to .01 magnitude?

That is an average of three estimates using different stars. It can be rounded up to 11.1

[robin_astro]

There is some complete nonsense posted on TNS today from people who have not read how to report events like supernovae etc (probably soon to be cleared out)

https://www.wis-tns.org/object/2023jfz

apparently a second supernova in M101 at mag -12 !!  and coordinates nowhere near

https://www.wis-tns.org/object/2023jgd

SN 2023jxf claimed to have been imaged at mag 7.77 on 13th May but not at  the right coordinates

 

I can see us not being allowed access to TNS at this rate if we are not careful

 

Robin

[rawhead909]

Cloudy all week of what I thought would be my last new moon period of this year's galaxy season. Then, last night, one night of mostly clear skies immediately before I leave the country for 3 weeks. Yeah, I still took out my EdgeHD800 for a 2 hour session on M101.

 

Comparing with a couple of TYCHO-2 stars, specifically TYC3852-78-1 (10th mag) and TYC3582-468-1 (9th mag), it looks like SN2023ixf is in 10th mag territory.

 

EdgeHD800 + 0.7x reducer + ASI071mc, 220 gain, 60s x 130, Bortle 6 skies (Albuquerque, NM)

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Edited by rawhead909, 23 May 2023 - 04:50 PM.