Bill S

Peter, I was using an f/5 200 mm Newtonian with a 0.5x focal reducer making the scope about f/3.5. Lodestar X2 camera. All mounted on an HEQ5 Pro. Software was Starlight Live for capture and Jocular for live stacking and stretching etc. The snapshot I showed is 3 x 15 S. Sky brightness SQM was was 19.90 so Bortle 5.

I've had no chance to observe comet 12P but I have been looking for a few others. Last night I looked at 2023 A3 . Here's a snapshot. At least there is a hint of a tail.

Mag 11. Still 3 AU from Sun. Possible bright comet in the future. Around October 2024. Mag 0 or better. I'll believe it when it happens. Watch this space...

I looked at a couple more supernovae on 12/13 April.

2024efn Discovered 12 March Currently mag 15.9. Another type IA. ~300 Mly

The other one was 2024cld. Discovered 13 March MG 16.0. Type II ~132 Mly

A clear night gave me the chance to have a look at some supernovae. I also caught up on December 2023 to March's Webb Deep Sky Society's Galaxies of the Month/ (I may post these separately.) I used the Rochester supernova site to find details and compare my snapshots with others' images.

First up was 2024ehs. Discovered 15 March. Currently mag 14.3 Type II (i.e. a core collapse of a large star at the end of its life)

The second one I looked at was 2024bch. Discovered 29 January. Currently mag 14.6  Type Iin. This one is also a core collapse supernova. However it's a rarer type.

Type IIn have narrow hydrogen emission lines in their spectra (hence the 'n'). The special properties of this type are thought to be due to interaction of the expanding supernova with

material around the star, the circumstellar medium.

I then looked at 2024exw. Discovered 4 March Currently mag 15.0 Type II. The large bright galaxy to the top left of the snapshot is M98.

Finally I looked at 2024gy. Discovered 4 January. Currently mag 14.8 Type IA. (i.e this is the type of supernova where the two stars are involved and material accretes on a white dwarf until it reaches a limiting point (Chandrasekhar limit, about 1.4 the Sun's mass) and explodes. They are useful standard candles for working out the distance of the host galaxy. Peter C65 recently posted a set of images of this galaxy and supernova showing them over several months.

200mm F/5 Newtonian with  focal reducer making it about F/3.5. Lodestar X2 with Starlight Live and Jocular.

Just need a few more clear nights!

I like to have a bit of look for some of the supernovae listed on the Rochester site (https://rochesterastronomy.org/snimages/).

One that I looked at during March is SN 2023bee in NGC 2708 (Hydra). This was discovered at the beginning of February and is said to have reached a maximum brightness of about 13. It was a Type Ia. I also looked for it a few days ago and it was still visible but noticeably dimmer.

I uploaded images from the March and April viewings to astrometry.net and plate solved them. I then loaded them into ASTAP to see if I could get reasonable magnitudes.

The March one came out as 14.0. A result published around the same date on the Rochester site was 14.2 and marked V, so presumably a photometric V filter was used. The April figure for me was 15.7, The closest date's Rochester result was 15.4 G (presumably a green filter).

The supernova looks a long way out from the main part of the galaxy.

And some more Arps (new to me) from a couple of recent sessions. Two nights observing in a row - amazing.

Arp 83

NGC 3799 and 3800. Bright arm probably due to tidal interaction. The disturbance may lead to more star formation.

Arp 263

Irregular galaxy. NGC 3239. Arp class Irregular clumps. Described as a bit of a train wreck. See also http://articles.adsabs.harvard.edu/full/1990PASP..102...41K

Arp 94

Arp 94 the large component, NGC 3227, is an unbarred spiral. NGC is a 3226 smaller dwarf elliptical galaxy.

NGC 3227 is a Seyfert with an active galactic nucleus.

Arp 232 is NGC 2911 and was classified by Arp as being neither spiral nor elliptical.

Arp 307 is NGC 2872, NGC 2873 and NGC 2874. The two larger ones were discovered by William Herschel but it took the 72-inch Birr telescope to see NGC 2873 for the first time.

Arp 335 – NGC 3509 was classed by Arp as Miscellaneous! It has been described as a possible double (i.e. merging) galaxy but this is debated. A fascinating shape.

Arp 43, which is IC 607, is a face on spiral galaxy. It’s rather small in my image but there certainly seems to be quite a lot of detail and it has a bright core.

An enjoyable couple of nights.

Arp 242. Ah yes Martin, I thought it looked familiar. Here's a shot from exactly 3 years ago. A bit longer exposure and I've inverted it to show the faint tail of NGC 4676B. Did a bit more Arp spotting last night and the night before. I must sort through them.

A bit of an Arpathon. Just a few hours of observing - picking up some objects that I have not looked at before or have not realised they were Arp galaxies.

Arp 89 NGC 2648. PGC 24469 is visible just to the side. Some interaction going on.

NGC 2375 interacting with 2735A. About 175 million light years away.

I like the long swirly arms on Arp 243. This is NGC 2623. Wikipedia tells us NGC 2623 is the result of two spiral galaxies that have merged. Scientists believe that this situation is similar to what will occur to the Milky Way, which contains the Solar System, and the neighbouring galaxy, the Andromeda Galaxy in four billion years. Something to look forward to!

Arp 247 is a galxy cluster IC 2338, UGC 04383 and IC 2339.

Arp 215 is NGC 2782. It is a Seyfert 2 galaxy. In other words an active galaxy - the 2 designation refers to spectral characteristics. They have a supermassive black hole with an active accretion disc.



Arp 315 is three galaxies – NGC 2830, 2831 and 2832 – from right to left. These, along with 80 more are part of Abell 779. Located about 300 million light years away.




Arp 283 is NGC 2798 and 2799 and they look to be interacting. About 85 million light years away.



Arp 202 is NGC 2719 and 2719A. 

NGC 3395 was the Webb Deep Sky Soc Galaxy of the Month for March 2023. Also known as Arp 270 and VV 246. The interesting article on the Webb DSS site (https://webbdeepsky.com/galaxies/2023/) explains that it is thought that the galaxies are in the early stages of interaction.

OK, that's quite enough for now!

That’s interesting. I’ll definitely want to read up about that and see if I can see any of the details you’ve managed to capture.

Thank you for sorting that out for us, Robin.

Re. The offset figures.

Martin Meredith's suggestion that the offset refers to a nearby bright star is reasonable because, as he says, the front page of the Rochester supernovae website talks about that.

There is another possibility. Some details of supernovae refer to an offset from the centre of the host galaxy. For example

The ASAS-SN Bright Supernova Catalog – IV. 2017 ...   '...we report these coordinates in Table 1. The offsets between the SNe and the centers of their host galaxies are also reported in the Table...'

https://arxiv.org/pdf/1811.08904.pdf

In this paper the offsets are in arcseconds.

It's of interest what the offset refers to but not of importance for using the website so far as I can see.

Thank you for your interest and comments. Happy supernova spotting!

Regards

Bill

Incidentally I still find it amazing that I could see the NGC 5894 and its supernova so easily. I posted an 8 minute snapshot to show things clearly but things were perfectly obvious in a 15 second sub.

Hello Pete

Yes, indeed. The Rochester one is where I normally look.

Cheers

Bill

One from a few days ago 29 September. The host galaxy is NGC 5894, an edge on spiral galaxy about 130 million light years away. The galaxy is listed as SBm. The supernova was discovered on 22 July this year and is a Type II i.e. a core-collapse. I was pleased to see it is was still clearly visible.

The same night I also looked at NGC 6745 to see if I could see SN 2022prr. This was discovered on 27 July. With a bit of wishful thinking I believe I can see it. The galaxy is an irregular galaxy about 206 million light years away. The supernova has been classified as a Type IIn. The n refers to particularly narrow spectral lines possibly linked to interaction of the ejected material with gas around the star.

Bill

Ooh yes, Martin. I see what you mean. I had another look at this early this morning and here's a snapshot labelled up with the ones you drew attention to. As you say, various other objects around too.

NGC 660 a polar ring galaxy.

Came across this when I was rambling around this part of the sky (Pisces).

Polar ring galaxies have an outer ring of dust and stars that is rotating around the main body of the galaxy. Quite probably the result of a galactic gravitational  interactions or stripping material from a passing galaxy. This one is 45 million ly away.

When I finished collecting subs I noticed that some cloud had come in, so perhaps it would be worth another look.

It may be worth looking for other examples of this type of peculiar galaxy.

And it was quite cosy around 15 degC.

Bill S

During the early morning of 5 July I had a look at some PNs in Hercules. NGC 6210 was listed as an object of interest for June by the BAA Deep Sky Section / Callum Potter and discussed in an earlier BAA Journal article. https://britastro.org/wp-content/plugins/baa-frontend-tweaks/baa-check-file.php?filename=2022/06/NGC-6210-A-forgotten-planetary-nebula-in-Hercules.pdf.

It is known as the Turtle Nebula and is about 6000 ly away and Mag. 8.4. I took LRGB subs (5 seconds each) using Starlight Live feeding into Jocular for live stacking.

Another one I looked at was NGC 6058 which is 13,000 ly away and Mag 13. Again colour helps.

The third Hercules PN was Abell 39. This is about 3300 ly away and mag. 13.7. This was a bit ghostly and my snapshot consists of 40 L and 10 each of R, G and B.  I maybe need to go back on another darker night to look at this almost perfectly spherical planetary nebula again.

All my shots were with a Lodestar X2  and my 200 mm Newtonian at f/5. I usually use a focal reducer but left it out for these observations.

I have had few opportunities to do some observing for some weeks but I had cleaned the mirrors of my Newtonian and wanted to check things were something like. I managed a session just after midnight (BST) 20/21 June.  Not astronomically dark so concentrated on a few brightish objects including M27 and M57. Having been to the Webb Deep Sky meeting on Saturday in Cambridge I was full of enthusiasm for planetary nebulae but decided to leave a good look around for darker nights.

The brightest comet around looks to be C/2017 K2 PanSTARRS. It's about mag nine in Ophiuchus, 1.9228au from Earth and 2.8560au from the Sun. 15 second subs showed it well and Jocular allowed me to remove three subs spoiled by a satellite trail. Hyper stretch brought out the magnificent coma and evidence of a tail. It should be at its brightest, mag 8, in December but will only be visible in the southern hemisphere.

It may not have been dark but at least it was warm.

7 x 15 seconds 200mm Newtonian ~f/3.5 Lodestar X2, Starlight Live + Jocular.

Bill S

Rob, thanks for mentioning the article. I've bought the pdf version of the July issue with the article from the Astronomy Now online shop.

The scope is a 200 mm f/5 Newtonian with a focal reducer making it about f/3.5. The camera is a Starlight Xpress Lodestar X2. The snapshot is using 12 x 15 second subs. Live stacking and processing using Jocular. The supernova was clearly visible in just one sub. 

 I snapped this the other night. It's a fairly easy one. Showed up well in just one 15 second sub in Jocular. The large galaxy is M60. SN2022hrs (= ATLAS22mip) (= ZTF22aafoqrd), TNS discovered 2022/04/16.619 by Koichi Itagak.

The galaxy (NGC 4647) is about 63 Mly away and is classed as SAB(rs)c. It is interacting with M60 and the pair are Arp 116.

The two galaxies overlap in a line of sight sense in longer exposures and so there have been suggestions that the supernova could be in M60 rather than NGC 4647. The supernova is around magnitude 12.6 and is a Type 1a (white dwarf accretion from its binary companion leading to the the supernova).

NGC 4298 and NGC 4302.

These two galaxies are the subject of the Webb Deep Sky Society's Galaxy of the Month for April by Owen Brazell. (See https://www.webbdeepsky.com/galaxies/)  They are in Coma Berenices and are part of the Virgo Group. They were discovered by William Herschel on 8 April 1784 so it will soon be their 'observational birthday'. They are about 55 Mly  away (Mark Bratton in The Complete Guide to the Herschel Objects says 49 Mly). NGC 4298 is SA(rs)c  and is a flocculent spiral i.e. it is patchy rather than having a well defined spiral. I think I have managed to catch that in my snap. NGC 4302 shows a clear dust lane in its edge on view. It is an active Seyfert galaxy and said to have box/peanut bulge implying the presence of a thickened bar.

The exposure time was 15 seconds per sub.

I put your picture through astrometry.net to plate-solve it and then loaded it into ASTAP to annotate the DSOs.

PGC 49480 is also catalogued as UGC 8841.  You can look in Simbad etc for more information.

e.g. https://simbad.u-strasbg.fr/simbad/sim-id?Ident=UGC++8841

Just got my contribution ready to post and saw you had sorted it out anyway.

Cheers

Bill

Over the past couple of clear nights I had a look at a few supernovae. Two recent ones are shown here.

The first is SN2022ewj in NGC 3367. The galaxy is an SB(rs)c 113 Mly away. The supernova is magnitude 15.9 and is a Type II (i.e. core collapse) discovered on 19th March. The misty background in the snapshot is due to clouds that were passing over.

The second one is SN2022eyj in UGC6312 in Leo. The galaxy is a spiral type SA at a distance of about 293 Mly (I think). The supernova has a magnitude of about 16 and is a Type Ia i.e. a binary system where material has accreted onto a white dwarf and reached the Chandrasekhar mass and exploded. It was discovered on 22nd March.

There's always summat!

Prompted by the recent views views of Arp 82 posted by AKB towards the current end of this thread https://stargazerslounge.com/topic/349834-cancer-arp-82-shk-185-hickson-37/?do=findComment&comment=4226745 I had another look at this fine specimen last night.

Rather a lot of subs because I left it running while I popped into the lounge to talk to my wife!