#47 Leo Galaxies: Abell 1367

I have stopped observing in Leo for this year, as it is getting into unfavourable skies for me.  I am hoping to eventually observe all 364 NGC objects in the constellation, and in two seasons of observing I have managed to view 64 of them!  Only 300 more left to see.

In the all-sky edition of Unranometria is a closeup chart of a galaxy-rich area in Leo.  Chart A-11 is a pinpoint view of a tiny section of main chart 72, left page.  Last year I only managed to view one galaxy within chart A-11, and it was just outside the Abell 1367 boundary.  This year I completed observing the galaxies within the chart, viewing all of the NGC objects, as well as the lone IC galaxy.  I even threw in a few UGC galaxies, as they were brighter than some of the NGC ones.  It took several nights with exceptional skies.

Once you know your way around Abell 1367, you can view all of the objects easily in a very short time, kind of like a mini-Messier marathon.  However, initially it takes a long time to properly identify which galaxy is which.  Most are faint, and well beyond 12th mag.  I  consider anything with a visual mag. of 12.5 or brighter to be an easy object for a 12" scope in a good sky.  12.5 to mag. 13 is considered more difficult, but a reasonable target.  Mag. 13 to 13.5 requires good seeing and some patience, as well as higher magnifications.  13.5 to 14 can be considered difficult objects, especially if somewhat large, or if edge-on. Below mag. 14 really requires an expert eye and pinpoint accuracy, and thus the close up chart becomes very valuable.

Tackling a project such as Abell 1367 is an excellent way to challenge yourself (with a 12"-14"), and offers a chance to spot very faint objects that might be harder to locate otherwise.  If you have never had much success with very faint objects, this might be a good place to try some.

I will first discuss the objects that lie just outside the boundary of Abell 1367, and then proceed to the actual galaxy cluster itself.  Once within the cluster, I always begin with a bright galaxy that is easy to identify, and then star and galaxy hop from there.

Uranometria 2000, Chart A-11, showing galaxies in and around A 1367 that I observed.

V.= Visual magnitude.

sb= surface brightness

eg 3805:  1'.4 x 1'.1:  V. 12.7; sb 13.2:  Preceding the main group, this was my first target and easy to spot.  Quite dim.  Viewed in 2013.  All others viewed in 2014.

http://www.ngcicproject.org/dss/n/3/n3805.jpg

eg 3787:  0'.4 x 0'.3:  V. 13.7; sb 12.1:  Located at 200x, where it was round and tiny.  Moon was up, too (5.5 days old!).

 http://www.ngcicproject.org/dss/n/3/n3787.jpg

eg 3827:  0'.9 x 0'.8:  V. 13.3; sb 12.6:  Located at 60x, though faint.  Image improves up to 200x.  Averted vision shows a larger object than with direct; round with a bright middle.

http://www.ngcicproject.org/dss/n/3/n3787.jpg

UGC eg 6670:  2'.8 x 0'.8:  V. 12.9; sb 13.6:  Located at 100x, and viewed well up to 200x.  Very oval, relatively bright and quite large.  Within a bright star field, it lies between 2 stars, mag. 11 and 11.5.

eg 3883:  2'.8 x 2'.3:  V. 12.6; sb 14.5:  Don't let the 12.6 fool you--this one is quite dim.  Located at 100x, it was large and slightly oval.

 http://www.ngcicproject.org/dss/n/3/n3883.jpg

eg 3910:  1'.6 x 1'.2:  V 13.1; sb 13.9:  Spotted easily at 100x, it has a faint star very near, north.  Up to 200x was used to see the oval shape.  Quite bright overall, with a bright middle.

 http://www.ngcicproject.org/dss/n/3/n3910.jpg

ABELL 1367

eg 3884:  2'.1 x 1'.4:  V. 12.6; sb 13.7:  Located at 100x, it was bright enough though dimmed by a nearby 7 mag. star.  Very elliptical.  125x and 150x showed a bright center, sometimes appearing star-like.

 http://www.ngcicproject.org/dss/n/3/n3884.jpg

UGC eg 6725:  1'.2 x 0'.7:  V. 12.9; sb 12.6:  Confirmed sighting at 125x, the galaxy had a stellar nucleus.  Oval and much dimmer than 3884.  Best with averted vision.

UGC eg 6719:  1'.1 0'.7:  V. 13.6; sb 13.2:  Located at 100x, it was much easier to see than U6725!  Bright and oval at 125x.

eg 3886:  1'.2 x 0'.9:  V. 13.2; sb 13.4:  An easy object at 100x, and it remains bright up to 200x, even with direct vision.  Oval shape unconfirmed.  North preceding two faint stars, mag. 11.5 and 11, in a line with it.

 http://www.ngcicproject.org/dss/n/3/n3886.jpg

eg 3861:  2'.4 x 1'.5:  V. 12.7; sb 13.7:  Seen at 100x, and on up to 200x.  Not large, but elongation is easy to see.  Best with averted vision, as there is a relatively bright star in the field.

 http://www.ngcicproject.org/dss/n/3/n3861.jpg

eg 3873:  1'.1 x 1':  V. 12.9; sb 13.7:  These two galaxies became favourites of mine, and I 

eg 3875:  1'.3 x 0'.3: V. 13.7; sb 12.3)  observed them over many nights.  Located at 100x, the very close pair at first appeared as one larger elongated haze.  However, at 125x, 150x, 187x and 200x the object clearly showed two bright centers, especially with averted vision.  3873 was the brighter of the pair, and round.  3875 appeared fainter, smaller and noticeably elongated.  Though definitely seen as two close galaxies, at times it did appear as one larger, unusual object.

 http://www.ngcicproject.org/dss/n/3/n3873.jpg

eg 3860:  1'.3 x 0'.7:  V. 13.4; sb 12.7:  This object proved tricky at first, but posed no problem on a superior night.  Oval, faint but not difficult.  Lies opposite eg 3873 and 75, with a pair of 11 mag. stars between.

 http://www.ngcicproject.org/dss/n/3/n3860.jpg

eg 3842:  1'.2 x 1':  V. 11.8; sb 12.2:  The brightest galaxy on the chart, and the home base for many other fainter galaxies.  Makes a nice triplet with 3837 and 3841.  Located easily just south preceding a mag. 11 star, one of 4 in a line running NE to SW.  Just slightly oval at 200x, and still very bright.

 http://www.ngcicproject.org/dss/n/3/n3842.jpg

eg 3841:  0'.9 x 0'.4:  V. 13.8; sb 12.5:  Much fainter than eg 3842, and elongated.  Makes a close triangle with 3842 and the 11 mag. star.  Shows well at 187x with 3842.

eg 3837:  1' x 0'.9:  V. 13.3; sb 12.9:  Easy to locate south following 3842, though not nearly as bright.  3841, 42 and 37 all fit nicely at 125x.  Round.  Near the 2nd star in a 4-star chain.

eg 3845:  0'.8 x 0'.3:  V. 14.2; sb 12.5:  A very faint slash was seen at 100x, and seen with averted vision up to 150x.  Just north of 3842 and 3841, and north preceding that 11 mag. star.

eg 3844:  1'.7 x 0'.3:  V. 14; sb 12.6:  Large and oval, though occasionally glimpsed with averted vision as a long slash.  Not that difficult!

 http://www.ngcicproject.org/dss/n/3/n3844.jpg

eg 3840:  1'.2 x 0'.8:  V. 13.7; sb 13.4:  Actually quite small and nearly stellar.  More difficult than it would seem.  Round with averted vision.

eg 3851:  0'.3 x 0'.3:  V. 14.7; sb 13.2:  Located opposite the 11 mag. star in relation to 3841.  Found at 100x, it was nearly stellar, round and fuzzy.

eg UGC 6697:  1'.5 x 0'.3:  V. 13.6: sb 12.6:  Located at 187x without much difficulty, just preceding 3842.  Oval.

eg I. 2951:  1'.4 x 0'.7:  V. 13.6; sb 13.7:  Follow the line of 11 mag. stars from 3842 SW.  Just south preceding the third star is this faint galaxy, nearly attached to an even fainter star.  Very faint but not difficult.  Possible stellar core at 200x.

eg 3862:  1'.6 x 1'.6:  V. 12.7; sb 13.7:  A large galaxy with a bright middle, much easier to locate 

eg I. 2955:  0'.4 x 0'.3:  V. 14.1; sb 13.7) than most other Abell 1367 objects.  Noticed at 100x and also observed well at 125x and 150x.  At 187x the galaxy began to appear suspicious, as if quite elongated!  200x and averted vision showed 2 galaxies!  I. 2955 is almost adjacent, and not plotted on Uranometria.  A fun discovery!

 http://www.ngcicproject.org/dss/n/3/n3862.jpg

eg 3857:  1'.4 x 0'.7:  V. 14.1; sb 13.4:  Seen with averted vision at 100x and 125x.  It appeared round.  Mag. 8.5 star hampers the view.

eg 3859:  1'.2 x 0'.3:  V. 14.1; sb 12.8:  Though spotted at 100x and 125x, the same 8.5 mag star as in 3857 interferes with viewing.  The star, 3857 and this galaxy make an equilateral triangle.  At 150x and 187x, the galaxy is large and oval.

 http://www.ngcicproject.org/dss/n/3/n3859.jpg

eg 3868:  0'.8 x 0'.3:  V. 14.4; sb 12.7:  68 appeared pretty large, though faint.  68 and 67 are 

eg 3867:  1'.5 x 0'.6:  V. 13.3; sb 13) elliptical with averted vision.  200x shows both galaxies quite 

eg 3864:  0'.9 x 0'.7:  V. 14.8; sb 14.1) well.  64 is very faint and round, likely the most difficult member of the Abell 1367 NGC.

 http://www.ngcicproject.org/dss/n/3/n3867.jpg

eg 3821:  1'.6 x 1'.4:  V. 12.8; sb 13.3:  Located at 100x and also viewed at 200x.  Not difficult to locate.  The center had two bright spots, likely a bright core and a foreground star.

http://www.ngcicproject.org/dss/n/3/n3821.jpg

eg 3816:  1'.9 x 1'.1:  V. 12.5; sb 13.2:  First located at 100x, but afterwards seen as a faint elongated slash at 60x.  At 100x and 125x it was bright and quite elongated, with a bright middle and a large amount of fainter outer haze.  Quite a decent object, one of the brightest members of Abell 1367.

 http://www.ngcicproject.org/dss/n/3/n3816.jpg

There you have it!  I really enjoyed my visit to this remarkable area, and will return to it next season for  another long look.

Mapman Mike

#46 Monthly Summary #3--April/May 2014

There were only three outings this lunar month, and one was for a self-hosted star party on our back deck for some of my music students.  We were also away for a week, missing one or two clear nights on approach to new moon.  Not one of our nights was a fine, clear night.  The final one started out promising, but we saw clouds move in just after dark, and were soon clouded out completely (despite the weather predictions of "mostly clear").

A total of 9 new NGC/IC  objects were observed, and one that was observed many years ago with the 8". Officially, all objects observed were galaxies.  However, I spent my time with a few globulars, doubles, and Mars, Jupiter and Saturn.

LEO

eg 3016: 1'.3 x 1'.1; Mag. 12.9:  One of a galaxy quartet, but my sky conditions changed before I could sort everything out.  Though smaller and fainter than nearby eg 3020, this one is not difficult.  Round, somewhat bright middle, best at 125x.

eg 3020:  3'.2 x 1'.8:  vis. mag 11.9; sb mag. 13.5:  Easy to spot, very large, oval, and a slightly bright middle.  Recommended object.  I will likely have to wait until next year to find the other two.

eg 3837:  1' x 0.9:  Mag. 13.1: In Abell 1367, an area crammed with galaxies.  Don't come here with a 12" scope unless you have a very detailed star chart!  I use the close-up one in the back of Uranometria 2000.  An easy object but not too bright.  With two other NGC at 125x (see below).

eg 3841:  0'9 x 0'4:  Mag. 13.15:  A close pair with the much brighter eg 3842, and a triple with eg 3837.  The is the smallest of the three, a faint, elongated haze that makes a triangle with eg 3842 and an 11 mag. star.

eg 3842:  1'.2 x 1':  A large galaxy, very easy to see, just south preceding a mag. 11 star, one of 4 in a line NE to SW.  Makes a nice pair with eg 3841 at 187x, and a triple galaxy at 125x with eg 3837.

 eg 3860:  1'.3 x 0'.7:  Mag. 13.05:  The first night I tried for this object I could not find it.  However, on a different night it posed no problem.  Oval, faint, but not too difficult to study.  On the preceding side of two N/S stars, and making a triangle with them.

eg 3873:  1'.1 x 1':  Vis. Mag. 12.9:  One of a close pair of galaxies, and the brighter of the pair.  Located just following two stars in a N/S line, not far from eg 3860.  Round.  Double galaxies seen at 125, 150 and 173x.  Recommended pair.

eg 3875:  1'.3 x 0'.3:  Vis. Mag. 13.7:  Fainter, smaller and elongated.  Sometimes it looked like one galaxy, but with good seeing and higher power it was a double!  3875 seen best with averted vision.

eg I. 2951:  1'.4 x 0'.7:  Mag. 13. 65:  Very faint but not difficult to see.  Stellar core noted at 125 and 200x.

BOOTES

eg 5523:    4'.7 x 1'.1:  A nice, bright and large galaxy, though I saw it as clouds and haze were rolling in.  I will return here first in the new session.  Seen previously with the 8", and quite impressive in the 12".  Cigar-shaped and recommended.

Mapman Mike

#45 Two Spring Globular Clusters

          Any seasoned observer knows that Spring is galaxy season.  The skies are rich with bright galaxies, and armed with a 6” telescope the best and brightest can be enjoyed.  With our club’s 14” scope (RASC Windsor), most of the fainter NGC list can be picked off, too.  Uranometria 2000 lists over 26,000 galaxies and/or galaxy clusters in its charts, a daunting task for any one person to observe or photograph.  Until summer constellations begin to rise later in the night, there is not much to see in the way of clusters.  In a future Spring post, I would like to discuss in greater detail some of the galaxy wonders of Leo, and not just the one famous triplet, but a number of other “triplets” as well.

            This time, however, I am turning to a pair of globular clusters, one of them a highlight of the entire flock.  Uranometria 2000 plots 170 globulars, including those inside the Magellenic Clouds.  I’m not certain how many are observable from northern latitudes, but it seems reasonable to assume that observing the entire viewable list is not too daunting a task.  We all know that the summer sky is crowded with globulars, though after seeing too many in short order they can tend to look somewhat similar, at least in smaller scopes. 

If you did not catch the recent Hubble view of M5 published in APOD on April 25^th, you should stop reading now and go take a look ("Astronomy Picture of the Day).  Hubble’s view of M5 is the perfect image of this object type, and the image we are all seeking when we go to the eyepiece, whether with a 6” mirror or a 36”.  I am convinced that globular clusters alone are responsible for most of us wanting bigger and bigger mirrors at our disposal.

            M5 is not well placed in early spring skies, but a worthy competitor is.  M3 (gc 5272) is one of the finest globulars in the sky, and makes a very refreshing sight after viewing so many galaxies.  Finding M3 is easy.  Locate Arcturus, and then nearby Eta (just south preceding it, mag. 2.5).  Make Arcturus and Eta the east-west baseline for a right-angle triangle, shooting north twice the distance of that baseline (see map, below: note M53 is also shown, but is not part of this discussion).  At a visual mag. of 6.3, even in binoculars M3 is impressive.  It resolves nicely in a 6” mirror, and in my 12” at 170x I’m beginning to get that Hubble feeling.  The main body spreads out over 18’, though outliers go well beyond.  The brightest star is mag. 12.7, so in a really dark sky smaller scopes will partially resolve this cluster nicely.

            By comparison, the second globular is much harder to see and resolve.  GC 5466 can be located 25’ following M3, and looks impressive enough on paper.  Its combined visual mag. is 9.2.  However, it is spread out over 9’ and the brightest star is only mag. 13.8.  In a great sky this one is barely visible in a 6” scope, and I have swept past it with the 12”.  Once located, it provides another wonderful lesson in interstellar distances.  In the larger scope the centre shows a slow burn, rather than the hot intensity of M3.  Resolution of stars is more ephemeral.  Patience is needed to begin to see the wonders of this large but very faint object.  Still, it is a gem and would be worth a trek to the club observatory’s 14” to see.  In fact, it would be better to begin with gc 5466, as our observatory scope will track right to it.  After observing the fainter object for a time with different eyepieces, moving to M3 will be guaranteed to give the viewer a rush.

            Amidst a night of viewing Spring galaxies, I always enjoy stopping for a break and viewing these two globulars.  Even after dozens of times I still enjoy the contrast and quiet spectacle they provide.

Mapman Mike