15 replies to this topic

[CrazyPanda]

Recently a member in another astronomy community wrote an observing report about this galaxy group in Leo. I hadn't heard about it so I decided to check it out tonight.
 

Locating the cluster was easy. I had a 12.5mm eyepiece in the focuser for 158x, and the first impression when seeing this group was "Wow!" The field was riddled with galaxies, and the more you looked and used averted vision, the more fuzzy blobs of light popped into existence.

 

The densest part of the cluster is centered around NGC 3842. Several galaxies packed closely together are visible here, but the whole region is filled with galaxies, so using Sky Safari Pro to identify what was what, I was able to observe 33 of them.

Here is a beautiful image of the field that I found:

 

https://delsaert.fil...l-1367_lrgb.jpg

Here's an annotated version depicting what I observed: https://i.imgur.com/GoCDpRe.jpg (same image as above, just annotated, so image credit goes to Bart Delsaert )
 

This is an incredibly beautiful region. I can see that I missed a couple seemingly obvious galaxies out away from the main clump, so I'll have to go back and re-visit.

 

Equipment

• 14.7" F/4.6 dob
• Paracorr Type 2
• 12.5 Nikon (158x) - used for initial observations
• 10 XW (198x) - used for majority of observations

 

Conditions

• 21.08 MPSAS in the direction of the cluster/group, 21.12 at zenith
• Great seeing
• Good transparency
• Annoyingly windy
• Very dry
• 15 degrees F (0 with wind chill)

 

Observed list

• NGC 3861A
• NGC 3860A
• PGC 36619
• NGC 3873
• NGC 3875
• NGC 3862
• IC 2955
• NGC 3867
• NGC 3868
• NGC 3857
• NGC 3859
• NGC 3851
• NGC 3842
• NGC 3841
• NGC 3845
• UGC 6697
• PGC 169975
• NGC 3873
• NGC 3844
• NGC 3840
• PGC 36503
• PGC 36502
• PGC 36510
• PGC 36486
• IC 2951
• UGC 6683
• UGC 6719
• PGC 36544
• PGC 36526
• UGC 6680
• PGC 139671
• NGC 3816
• NGC 3821

Edited by CrazyPanda, 29 March 2022 - 01:50 AM.

[StanH]

Abell 1367 is a very rewarding cluster.  My first observations were with an 8-inch SCT at the Texas Star Party in 1993.  Then in 1999 did a more thorough view of the cluster with a 17.5-inch Dobsonian.  All together I was able to pick out 144 galaxies in the area, though about 20 were background galaxies with one with a redshift as high as 0.1.

[starblue]

Sky Safari Pro 6 lists 388 galaxies under the Abell 1367 designation. Seems like with 33 you're about 10% of the way there.

[StanH]

Sky Safari Pro 6 lists 388 galaxies under the Abell 1367 designation. Seems like with 33 you're about 10% of the way there.

I wonder how many are actual members.  The list I went off of in 1999 had just over 200 galaxies in the area, though a lot at that time did not have redshifts determined yet to see if they were actual members.  Of the ones I observed that had Abell 1367 designations, 10 turned out to be background and two still do not have redshifts listed at the NED yet.

[CrazyPanda]

I wonder how many are actual members.  The list I went off of in 1999 had just over 200 galaxies in the area, though a lot at that time did not have redshifts determined yet to see if they were actual members.  Of the ones I observed that had Abell 1367 designations, 10 turned out to be background and two still do not have redshifts listed at the NED yet.

Yeah the Sky Safari list includes galaxies all the way out in Coma Berenices and other constellations. I figured that was a mistake but I don't know what the basis for the Abell catalog is.

 

Both this Leo cluster and the Coma cluster are part of the Coma supercluster, so maybe that's part of why they have the same designation, but it seems strange.

 

If it really has that many galaxies, then going through this list as thoroughly as I can will be a fun observing project.

Edited by CrazyPanda, 29 March 2022 - 08:27 AM.

[Voyager 3]

Sky Safari Pro 6 lists 388 galaxies under the Abell 1367 designation. Seems like with 33 you're about 10% of the way there.

But over half of those are >mag 16 .. 

[starblue]

But over half of those are >mag 16 .. 

So he'll have to work for it! 

[Voyager 3]

So he'll have to work for it! 

Work overtime to get a 20"? 

[Redbetter]

Abell 1367 is a very rewarding cluster.  My first observations were with an 8-inch SCT at the Texas Star Party in 1993.  Then in 1999 did a more thorough view of the cluster with a 17.5-inch Dobsonian.  All together I was able to pick out 144 galaxies in the area, though about 20 were background galaxies with one with a redshift as high as 0.1.

It is one that I have still not delved deeply into, only nibbled at one edge.  (This time of year has few good observing nights locally so Leo and Virgo have been sadly neglected.)  It is one I have been planning to get around to, but I need several straight nights and several labelled finder charts prepped in advance to give it a decent survey.  It is difficult to observe and make descriptions of even 30 galaxies down to threshold detection in a session for a single galaxy cluster before time is running out and the target area is drifting into brighter, lower sky.   

 

Albert Highe had made a project of this and some other Abell clusters.  His site is defunct now (health issues from what I gather) but can be reached via the wayback machine.  For Abell 1367:  link.  The page links seem to work as well (wayback links).  His Excel list is there of 205 galaxies (not all of them cluster members.)    Looks like he observed ~133 with a 17.5" scope.    Most of his listings are B magnitudes from what I can tell.  His visual limits seem to have been somewhere in the 16 V mag range based on the g & r magnitudes of some of the dimmer ones he observed.  That sounds like about what I would expect for that size scope.  

[StanH]

It is one that I have still not delved deeply into, only nibbled at one edge.  (This time of year has few good observing nights locally so Leo and Virgo have been sadly neglected.)  It is one I have been planning to get around to, but I need several straight nights and several labelled finder charts prepped in advance to give it a decent survey.  It is difficult to observe and make descriptions of even 30 galaxies down to threshold detection in a session for a single galaxy cluster before time is running out and the target area is drifting into brighter, lower sky.   

 

Albert Highe had made a project of this and some other Abell clusters.  His site is defunct now (health issues from what I gather) but can be reached via the wayback machine.  For Abell 1367:  link.  The page links seem to work as well (wayback links).  His Excel list is there of 205 galaxies (not all of them cluster members.)    Looks like he observed ~133 with a 17.5" scope.    Most of his listings are B magnitudes from what I can tell.  His visual limits seem to have been somewhere in the 16 V mag range based on the g & r magnitudes of some of the dimmer ones he observed.  That sounds like about what I would expect for that size scope.  

It was interesting to compare my list to his as I still have the hardcopy.  My original list was finalized April 17, 1999.  I used Guide 7.0, RealSky, Uranometria 2000.0, Webb Vol. 5, and the NED to put it together.  There were 216 galaxies found between RA 11:40.6 to 11:48.1 and declination of 19:10 to 20:49.  During my observations two more were added.  My list had more galaxies than Highe's though a slightly narrower area.  Many were anonymous galaxies found while examining RealSky and were not found in the other sources.  As a result many did not have magnitudes so I did not put a cap on how faint to go.  Only 87 galaxies had catalogued redshifts at the time though now of the galaxies that have been observed only two no longer have redshifts listed at the NED.

[bphaneuf]

Just enlarged the image.  Amazing!  NGC 3816 looks tidally disrupted in a major way.  Unable to find out anything about it, though.  Abell 1367 is on the list now!

Thanks again for sharing the info!

-b

[Redbetter]

I had observed 14 galaxies from the NE edge of this cluster last year (mix of NGC's, IC's, MCG's, CGCG's, UGC's, KUG, PGC and 2MASS.)  Last night, 4/3/22, I spent several hours logging observations of the galaxies in a strip of the central field from NGC 6783/5 and 3861  WSW to IC 2951.   Seeing was variable from average to good, and transparency was mediocre so I wasn't going super deep trying to pick up the smallest ones, instead sighting galaxies to just past 16 V mag.   Using two charts I prepared beforehand, it looks like I tallied 40 additional which was a lot to observe and describe in 3 hours with light dew, now I just need to get their catalog ID's.   

 

This still leaves a lot, since I haven't pursued the clump of the southern section, the rich center-north, and the northwest, not to mention some outlying areas with a few stragglers.   The richer portions remaining are on two other charts I made and brought with me, but I will need some additional charts for outlying areas.   I will have to cross reference with Highe's list to compare.  

[RLK1]

I observed a portion of this group last night, 3-24-25,  from my dark sky site, with 21.04 SQM readings, excellent transparency and average seeing conditions. Like the OP, I was centered around the area of NGC 3842 with all views in a 60 degree AFOV 12mm eyepiece with my 16" f4.5 dob. 

 

To sum it up, it was like raining galaxies in the field of view! Additionally, I could discern some surprisingly satisfying details in a some of the galaxies which added to the thrill of the observation.

 

The "Observer's Guide" notes NGC 3842 is situated in the heart of the group and is also its brightest member. 

 

I had just teased out some memorable views of Copeland's Septet before turning my attention to Abell 1367 but the latter was, as I like to say, definitely worth the price of admission!

 

It's well-situated for observation at this time of year from my location in SoCal, and if you're able, I'd certainly recommend revisiting the cluster or, if you've never seen it, go for it!

[Bill Barlow]

When I owned a C14 10-12 years ago, I viewed both of these distant galaxy groups.  Just finding them by star hopping was satisfying and knowing most of these galaxies are around 500 MLY away from Earth.  
 

Bill

[Keith Rivich]

I spent a little time in this cluster as part of Larry Mitchell's Advanced Observing program for TSP. With the 25" and SQM-L 21.3 skies I was able to bag a handful of galaxies using NGC 3842 as a anchor. Pretty much all of the galaxies down to around mag 16.5 within a degree or so from 3842. I'll work the entire cluster at TSP. 

[Akarsh Simha]

https://web.archive....ighe/a1367.html

https://adventuresin...gc1367notes.htm