#38 Monthly Summary # 8: October/November 2013

It's now been one year of observing with the 12".  When I first set out to find all the NGC objects I could from my location, I thought it would be a daunting and difficult task.  I had no idea.  I figured that pointing a 12" Dob into the overhead sky would reveal anything and everything I wished to see.  It did, but what a task!  I expected (and got) trouble low on the horizon (see my previous post), but did not expect that much difficulty with overhead skies.  Finding some of these little faint objects from the NGC list has been really, really hard!  However, the experience I have gained in the past year has been impressive.  Knowing the limitations of one's scope (and eyes) is so important to observing.  It has been a lot of fun finding my limitations.

The good news is that I have seen every NGC and IC object in Lyra and Cygnus, and I am nearly done with Cassiopeia!  Last lunar cycle did not produce a bonanza of clear nights.  There were three that worked for us.  My biggest conquest (well, one of them) was locating the final unseen NGC galaxy in Lyra.  I saw it 45 minutes after sunset in one of the clearest skies I have ever experienced.  What makes eg 6686 so hard to see is its faintness (obviously) and its proximity to a bright star (mag 7.5, which looks like a streetlight in a 12").  I tried a number of times this summer.  However, the sky on this night was as perfect as it gets, and "bingo," there it was, in all its faint fuzziness.

Other impressive accomplishments include locating (just barely) eg 45 in Cetus, and enjoying my best view ever of pn 246, not far away.  The three sessions saw us observe for 11.5 hours.  I snagged 21 new NGC objects and one IC, plus 9 open clusters from other catalogues.  I give the facts below.

LYRA

eg 6686:  Mag. 14.45.  Very faint and elusive, but visible at 125x and 150x.  Small and round.  This completes my work in Lyra!!

CASSIOPEIA

gn 896:  These two nebula appear together, separated by a small black lane.  896 is quite good with a filter, and is the brighter of the two.
gn I 1795:  Appearing with 896 at low and medium powers, it is involved with a mag. 9 star.  Both easy objects with the ultrablock filter on a very fine night.
eg 1343:  Mag. 13.5.  Located at 125x, and observed at 150x and 200x.  Faint overall, but showing a brighter middle, and noticeably elongated.  2 faint stars lie immediately north.

CETUS

eg 45:  Mag. 12.5.  One of the biggest challenges in Cetus for northern observers is this large, very low surface brightness galaxy.  After many tries, I saw it on this one superb night.  6.9 mag. and 9.9 mag stars make this even harder to see.  Expect faint patchiness, in at least two locations.  Located at -23 degrees.  Good luck.
eg 113:  Mag. 13.3.  Oval and faint, a brighter center was noted at 200x.
eg 114:  Mag. 12.9.  Paired with 118, this was smaller but somewhat brighter.
eg 117:  Mag. 13.8.  Difficult object.  Seen at 125x and 150x.  Round.
eg 118:  Mag. 12.95.  Larger than 114, but seen with it at medium powers.  Large and fainter.
eg 120:  Mag. 13.35.  Threshold object at 125x.  Noticeably elongated at 150x.
eg 124:  Mag. 13.1.  Tricky to locate.  Big and oval, best with a.v.  Close to 114, 118.
eg 132:  Mag. 13.2.  Easy to spot at 60x!  Round and ghostly at 100x.  Much brighter at 200x, and quite large.  Sits amidst three faint stars.
eg 145:  Mag. 13.15.  Oval, faint and best with a.v. at 100x, 125x.
eg 161:  Mag. 13.35.  Like a star out of focus at 125x.  Very small.  150x shows elongation.  200x shows a stellar core.
eg 173:  Mag. 14.1.  Ghostly at 125x, it was acceptable at 150x and 200x.  Very large with a low surface brightness, I wish to return here for a 2nd look.
eg 179:  Mag. 13.05.  At -18 degrees.  Spotted at 100x.  Oval with a bright middle or perhaps a star within.  125x and 150x shows well.
eg 209:  Mag. 12.95.  1 degree S of 179!  Small, round and very faint.  Appears to have a stellar core.
eg 255:  Mag. 12.9.  Lying at -11 degrees, 28', this one has proved impossible up till my one fabulous night.  Easy tonight!  Round and ghostly, like a planetary nebula.  Large at 125x (though considerably smaller than nearby pn 246).
eg 1070: Mag. 12.75.  Seen at 60x, 100x, 125x and 150x.  Round, faint but large.  Oval at 150x.
eg 1085: Mag. 12.8.  Small and faint.  Should be brighter.  Will return for a 2nd look.
eg 1137: Mag. 13.  Views improve at 125x and 150x.  Considerably elongated using a.v.
eg 1153: Mag. 12.35.  Small and faint.  Oval at 150x, with a brighter middle.

CLUSTERS FROM OTHER CATALOGUES

Cassiopeia

oc Be 4:  15 faint stars around a bright one.
oc Be 61:  Small, hazy patch at 60x.  Resolves at 125x upward, but very few stars. 
oc Be 62:  A dozen faint stars involved with a 5-star asterism.  Use high power.
oc Be 104:  S of star V639.  6 stars resolved at 250x, hampered by the variable.
oc Do 13: Large and widely scattered group.  About 40 stars at 100x, many of them bright.  Attractive group.
oc King 1:  Very faint at 60x.  150x shows 16 stars in 2 groups.  A bright group is adjacent.
oc Skiff j00584+6878:  125x begins to show a dozen stars, widely scattered.  Out of the way.
oc St 18:  Line of 5 bright stars.  2nd from west surrounded by faint stars.
oc St 21:  A 'V'-shaped group was noted, open end to the NW.  The line of stars in the S (running E-W) has a compact group of very faint stars around it.  The whole 'V' is attractive.

Mapman

#27: Deep Sky Lyra, Part 2: The Galaxies

Over five nights this summer, I spent about 19 hours re-observing Lyra.  This was my fourth in-depth visit since first encountering the constellation back in 1971.  This time, equipped with a 12" Dob, I went really deep in an effort to view every single NGC object within its boundaries.  I managed to snag 28 out of 30, likely requiring a darker sky or better eyes to nab the final two.  In Part 1, I discussed my encounter with the clusters and nebula of Lyra, including 1 non-NGC object.  This time I will discuss the NGC galaxies.  There are 27 of them, of which 25 were successfully located and observed.  Despite the wealth of double stars in Lyra, most of which I have observed, they will not be discussed at this time.  I am now planning Part 3 to deal with them.

 

Before setting out on our exploration of faint galaxies, a few ground rules must be laid out.  Before observing, I have the following information at hand in my field notes:  size of object, including length and width, and the visual magnitude and surface brightness of the object (see my earlier essay on mag.).  To simplify matters, I combine the visual magnitude with the surface brightness, thus:  if a galaxy is assigned a visual mag. 11 and has a surface brightness of 13, then I list the apparent magnitude as 12, simply splitting the difference.  This generally works pretty well in the field, and if not completely accurate at least it provides a basis for comparison between the galaxies.  However, if things are the other way around (visual 13 and surface brightness 11), things don't work out quite so well.  In this case, the true answer usually lies much closer to the visual side of things.  While my 12" mirror barely showed some of these objects, perhaps in a very dark, dry sky a smaller mirror would accomplish just as much.

 

I will begin by listing and very briefly discussing the Lyra galaxies in order of brightness.  Note that there are no showpiece galaxies here, though there are a few of significant interest.  After the top 3, there are no more with a combined magnitude of less than 13!

 

6703: 2'.7 x 2'.5--Mag. 12.35:  A veritable beacon of light compared to most other galaxies in Lyra!  The only galaxy I saw previously, using my Edmund 8".  In the same 150x field with 6702.  Though bright, it is not all that interesting.  In a lovely star field.

6702: 1.'9 x 1'.5--Mag. 12.9:  Useful as a comparison with 6703, the 2nd brightest galaxy in Lyra is getting pretty faint!  In the same field with 6703.  More oval than 6703.

6675: 1'.8 x 1'.3--Mag. 12.9:  I could also see this one with the mirror stopped down to 8".

 

6646: 1'.6 x 1'.3--Mag. 13:  A significant number of the galaxies are within easy star hop of Vega.  This was the first galaxy in Lyra I saw this year, thus it is one of my favourites.  There are two IC galaxies very close by, one easy and one not.

6792: 2'.2 x 1'.3--Mag. 13:  Takes high power well, and at 200x it was still pretty bright, quite large, and very elongated.  Two 14 mag. stars at the N end.

6688: 1'.6 x 1'.3--Mag. 13.05:  Also takes high power well.  Stellar core.  3 faint stars beside it.  First seen at 60x.

6692: 1' x 0'.7--Mag. 13.05:  Spotted at 100x near a colourful, wide double.  Very near a 9 mag star, so averted vision gives best views.  200x appropriate.

6671: 1'.5 x 1'.3--Mag. 13.1:  Easily spotted at 60x, within a bright, rich star field, and directly amidst a short, curving string of stars.  Stellar core and fainter halo obvious.  Fine up to 250x.  Faint star N.

I-1288: 1'.1 x 0'.7--Mag. 13.2:  In the same 100x field with 6646, above.  Smaller and fainter than that galaxy, but not difficult on a good night.  Between two faint stars.

6606:  0'.9 x 0'.7--Mag. 13.25:  Located at 60x.  Good views up to 150x.  Again, it is in a bright field of stars.

 

There you have the top ten galaxies, by brightness.  Told you there was nothing special.  Still, I enjoy the hunt, and also surprising others when you say that you are observing galaxies in Lyra (lots of them)!  Here are the rest, in order of brightness.  For some of these I wish I'd used the astronomy club's 14".  For the two I did not locate, perhaps I will use it.  The following galaxies were all seen best using averted vision.

6695: 1'.1 x 0'.7--Mag. 13.3:  Located SF a string of 3 bright stars running N-S.  Faint, oval.
6640: 1'.1 x 0'.8--Mag. 13.35:  Observed at 120x and 150x.  Not small, but faint.
6657: 1' x 0'.6--Mag. 13.35:  A wide slash at 120x and 150x.  Near 6640.
6713: 0'.4 x 0'.3--Vis. Mag. 13.4:  Because of its tiny size, the surface brightness of this is listed as 11 mag.  Don't be fooled.  Small, though not as small as one might expect.  Best at 150x.  Elusive.
6685: 1'.1 x 0'.9--Mag. 13.45:  Seen at 125x and 150x.  Very faint star pair nearby.  Round.
6700: 1'.4 x 1'--Mag. 13.5:  Oval, not difficult.  Seen well from 100x to 200x.  Very faint star involved or adjacent.
6710: 1'.7 x 1'--Mag. 13.55:  Bright field stars makes this one a challenge.  Quite small and faint.
6745: 1'.3 x 0'.5--Mag. 13.7:  Spotted easily at 100x just NP V547 and close to a mag. 9 star.  Seen well at 125x, 150x, and 200x, and possibly the most interesting galaxy of the bunch.  Very elliptical, lying between two faint star groups.  3 galaxies are colliding, and there is a remarkable Hubble Heritage photo of this object!  Easy to find using Uranometria.
6662: 1'.5 x 0'.5--Mag. 13.75:  Located at 125x, the elongation was not noticed.  Central area appeared stellar at times.
6663: 1' x 0'.9--Mag. 13.75:  Close to Vega.  Near a lovely triple star.  Brightness of star hampers location of this very faint galaxy.  Viewed over multiple evenings for confirmation.
6665: 1'.1 0'.6--Mag. 13.75:  This took several tries, but once seen was not difficult to view.  Oval at 125x and 150x.  Just S of a curving star group.
6740: 0'.9 x 0'.8--Mag. 13.95:  Visual mag. is 14.2.  Threshold object at 125x.  Round and better at 150x.  Just S of oc 6743.
6612: 0'.7 x 0'.7--Mag. 14.05:  Visual mag. is 14.5.  Took several nights to locate.  Found on the best of nights without difficulty at 125x.  Also viewed at 150x and 200x.  What else can one say about excellent sky conditions?
I 1289: 0'.7 x 0'.3--Mag. 14.1:  Visual mag. is 15!  Took several nights of trying.  Seen at 125x, 150x and 200x.  Oval and very faint.  Nearby 6646 and I 1288 much easier.
6672: 0'.2 x 0'.1:--Mag. 14.1:  Visual mag. is 15!  Seen at 150x and 200x.  A tiny, faint threshold object makes a close triangle with 2 stars, mag. 9 and 12.  Huzzah!

Two objects remain unseen.
.
I 1286:  Mag. 14.15: Immediately NP M 57.  Located within a faint circlet of stars.
6686: Mag. 14.45:  Too close to a bright star (7.5 mag.).



I really did enjoy my five-night tour through Lyra!  Next up, a deep investigation of Cygnus.
Mapman Mike