Cassiopeia Deep Sky: Prelude

     If you have been reading this blog for any length of time, you know by now that I am interested in observing as many NGC objects as I can.  The fact that I am in no real hurry, but will take my time observing each one, is a dead giveaway that I will never complete my project.  Even if I lived in New Mexico and had nearly year round access to great skies, my project would never be completed in my lifetime.  If I was interested in a mere glance at an object, and carried out marathon NGC observing sessions during clear nights, I might have a chance.  But as I have already indicated in an earlier post, this is not my idea of observing.  Of course there are many objects, faint galaxies for example, that do not require much observing time once located.  But there are so many wonders that repay long looks, using different eyepieces, and even involving some sketching, that observing more than 5 or 6 in one night is a challenging task for me.

     I have chosen several constellations to view as the seasons pass.  For late summer I will move on to Cygnus and Cassiopeia.  Later in the autumn I will return to studies of Cetus, then back into Lepus.  During the winter I will continue with Monoceros, then on to Leo once more in early spring, and Bootes later on.  I always have planned sessions ready at hand, though I often enjoy just wandering about up there, too.

     The deep sky objects of Cygnus were briefly discussed in the previous post.  Now it's Cassiopeia's turn.  Like Lyra (now completed) and Cygnus, my focus is on the NGC and IC objects.  However, since a 12" mirror can do so much more under a dark sky, I have also included clusters from other catalogues.  Many are very dim and small, but a few promise just as much fun and adventure as some of the better NGC objects.

     Cassiopeia has a grand total of 36 NGC objects, along with 11 IC ones.  These 47 objects are my main focus of interest.  29 of the NGC entries are open clusters, including M 52 and M 103 (and, of course, oc 7789!).  I can also look forward to 4 galaxies (2 already logged) and 3 galactic nebulae.

    The IC list adds 4 more open clusters, 4 nebulae, 2 planetaries and another galaxy. 

    In the "other" category come no less than 59 open clusters from catalogues besides the NGC.  It would appear that a few objects were overlooked back in the day by Dreyer and company!  Many of these, due to their faintness and small size, will get just a quick glimpse.  However, any special ones noted will get as much viewing time from me as an NGC object.

     I can therefore look forward to 92 open clusters, 7 galactic nebulae, 5 galaxies and 2 planetary nebulae in this wonderful constellation (100 deep sky objects!).  Using Uranometria All-Sky Edition, my clipboard notes are fully prepared, my mirror collimated and my eyepieces cleaned.  All I need now is a much later moonrise time and some great skies for observing.  Check back in mid-September to see how I am doing with my Cygnus and Cassiopeia project.

Mapman Mike

Cygnus: A Deep Sky Prelude

     With Lyra completed and summer constellations moving forward less and less each night due to shorter days, I have taken up the task of viewing the deep sky objects of Cygnus.  Later during the night I will switch over to Cassiopeia, but first I thought I would give an idea of what Cygnus has to offer for someone with a 12" mirror. 

     My first and primary goal is to view all of the NGC and IC objects.  However, Cygnus is loaded down with "other" objects as well, mostly open clusters from different catalogues.  I will briefly discuss each main category, beginning with the NGC.

     There are 57 NGC objects in Cygnus.  33 of them are open clusters.  While I have seen many of them with my previous telescope (8"), there are quite a few new ones for me to observe.  Things I have seen previously should look considerably different in my larger mirror.  In addition to the clusters, there are 9 planetary nebulae, 8 galactic nebulae and 7 galaxies.  M 29 and M 39 are also included in this NGC list.  Even this many objects could keep an observer happy for many viewing sessions.  It is doubtful I will get through them all this summer.

     There are 16 IC objects in Cygnus.  6 are galactic nebulae, 5 are galaxies, 4 are open clusters and 1 is a planetary.

     Finally come the other catalogues, mostly open clusters from Berkeley, Collinder and several others.  57 of these other objects are open clusters, many of them very small and faint, and truthfully probably worth just a quick glimpse.  There are 2 planetaries and 1 galactic nebula.  I have decided to largely pass on the PK planetaries, at least for this season.

     In total, I will be viewing 132 deep sky objects in Cygnus.  94 are open clusters, 14 are galactic nebulae, 12 are galaxies and another 12 are planetaries.  I have mixed in a number of double stars as well.  All of the objects are plotted and named on Uranometria All-Sky Edition, though the double stars are mostly unnamed in there.

     I already have a small start on Cygnus (see previous post), and am impatiently awaiting the time near last quarter moon when observations will get underway again.  With darkness falling a bit earlier now, even more time can be spent at the eyepiece if it is clear.  My next post will be a similar brief look at upcoming deep sky objects in Cassiopeia.
Mapman Mike

Monthly Update #5: July/August 2013

     At last!  Some clear summer nights with terrific conditions.  We even had a few such nights between last quarter and new moon, something that has been rare.  As a result, a large number of new objects were logged, and a few old classics.  During the observing month I managed to conclude my in-depth studies of Lyra.  I have now moved on to Cygnus and Cassiopeia.  While all three constellations have been examined in detail in past years with the 8", it is a whole new world up there with a 12".  Most of the fainter, previously invisible NGC objects are now available to me, expanding my viewing options significantly.  My earlier studies in Lyra saw me observe 4 NGC/IC objects.  This time around I went after 32 of them, plus one non-NGC open cluster!  Only two objects proved too faint or small.

     Searching for faint galaxies in Lyra (and now Cygnus) has the advantage of observing in overhead skies.  However, the disadvantage is the rich and bright star field surrounding many of them, making galaxy viewing quite challenging.  Of the 32 new NGC/IC objects observed this month, only 5 were non-galaxies.  Those consisted of a globular (M56), two open clusters and two planetaries (one being M57).  This entry will only deal with objects seen in the past month.  For the full Lyra details, see my two previous blog entries.

     For Cygnus and Cassiopeia, I have decided to not only search for NGC/IC objects not previously seen with the 8", but also to undertake a full but quick review of objects already logged with that instrument.  In some cases it's been 20-30 years since I have observed most of these objects, so it's likely time for a revisit.  While more time will be spent on the unfamiliar objects, I will try to spend some time with every cluster, nebula and other deep sky object in these constellations.  My to-do list is extensive, and it will take many sessions to complete.

     This past observing month I observed 25 new NGC/IC objects, as well as reviewed 8 others previously seen.  Most were faint galaxies, and most were in Lyra, but a few were also logged in Cygnus.  While none of the galaxies were outstanding, a few were well worth the hunt, and recommended objects.  The finest objects this past month were all ones I had seen years before.  I will list them in order of interest, beginning with the best and brightest objects newly seen and continuing on to the faintest of the faint fuzzies.  Then I will discuss previously seen objects.

NEW OBJECTS

eg 6764:  The brightest galaxy in Cygnus, and brighter than any of the ones in Lyra except for 6703 (see previous blog entry, below).  Worth seeking, likely making you one of the rare amateurs who know there is a pretty bright galaxy in Cygnus and have seen it!

eg 6702:  2nd brightest galaxy in Lyra, and a nearby companion to the brighter 6703.  Two for one.

pn 6765:  Lyra's "other" planetary.  10" or 12" recommended.  Unusual elongated shape.

eg 6688:  Involved with at least 3 very faint stars.

eg 6692:  Nothing special.

eg 6745:  Check out the Hubble Heritage photo of this object!  Easy with a 12"!

eg 6671:  An easy object, likely doable with an 8".

eg *I 4867:  Small, but bright and easy at moderate magnification.  Near two bright variable stars.
oc 6743:  Called non-existent in some sources, including my push-to computer.  It does exist, and exactly where Uranometria places it.  A bright star is surrounded by a faint cloud of very dim stars.  I counted 18 at 150x.

eg 6662; eg 6665; I 1289; eg 6710; eg 6743; eg 6740; eg 6700; eg6692; eg 6713; eg 6685; eg 6612; eg 6696; eg 6672; eg 6606; eg I 1289; eg 6783 (Cygnus); eg *I 1301 ( Cygnus).  All tricky.  Happy hunting!

*  A note about I 4867 (bright and easy for a 12") and I 1301 (very dim and extremely difficult, just south).  Some sources say they are the same object!  Not!!  Refer to Uranometria.

There you have it--25 new NGC and IC objects.  The only non-NGC object viewed this month was also new to me.  Ste 1 is a very large open cluster centered around Delta Lyra.  Bright and suitable for almost any aperture.  Lovely in the 4 1/4" Astroscan.  About two dozen stars with a 12".

PREVIOUSLY VIEWED OBJECTS

pn 6720--M 57:  Arguably the finest amateur object out there, except perhaps for M 42!  One of two objects I was unable to locate was a faint IC galaxy very close to M 57.

gc 6779--M 56:  Often overlooked in favour of more popular summer globulars, this one is not to be missed in a 12"!

oc 6791:  Resolving this open cluster is more difficult than many globulars.  A real beauty!

oc 6811:  A rich and lovely cluster, with a very fine field just preceeding.  Repays close viewing.  Plenty of brighter stars, and some very dim ones back there, too.  A 4" mirror just begins to resolve it!

oc 6819:  Smaller and not as rich as 6611, but not to be missed with a large mirror.  Unusual shape, and again in a very bright star field.  Use all magnifications, and then go back to lowest again.  Recommended!

eg 147:  A massive galaxy in Cassiopeia with a very low surface brightness, this one requires a great sky.  One of M 31's nearby cousins.

eg 185:  Very near 147, and also related to M 31.  Brighter, smaller and much easier to view than 147, but it is still huge!

eg 6703:  The brightest galaxy in Lyra and/or Cygnus, and a decent object for an 8" mirror.  6702 appears in the same field.

     It was a most enjoyable month.  I managed 7 observing nights out of the 14 available!!  Happy hunting!

Mapman Mike

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
 

 

 

 

Deep Sky Lyra, Part 1: Clusters and Nebula

     I have spent many happy hours observing in the constellation Lyra, first in July 1971 when I observed it over two nights from northern Ontario with my Tasco 4.5" Lunagrosso reflector!  I thought I had hit the jackpot when I found M 57, and again later with M 56, using those crappy .96 Kellner and Huygens eyepieces. 

     I returned with my Edmund 8" reflector in July 1978, also from a dark sky site in northern Ontario.  With such a big aperture and much better eyepieces, I enjoyed unrivaled views of both Messier objects, even resolving the outer edges of M 56 at higher powers. 

     In 1992, equipped with better books and maps, I once more found myself immersed in a study of Lyra, again with my trusty 8" reflector.  I was able to add two new NGC objects, the very challenging oc 6791, which the 8" managed to partially resolve at high power, and eg 6703, seen from my suburban backyard in Essex County, Ontario.  I was able to view the galaxy at up to 200x!

     Now comes July 2013.  Light pollution marches on.  Though I have doubtless observed the Ring Nebula many times since 1992, this marked my first official visit to Lyra in 21 years!  Equipped with the Uranometria Atlas, all sky edition, and a 12" reflector, this was a very different adventure.  There are a total of 29 NGC objects brighter than mag. 15 plotted on the atlas, along with 3 IC objects and one "other," an open cluster labeled Ste 1.  I also went after a few new closer and fainter double stars, and reviewed a number of old favourites.  However, this blog will only deal with the NGC and similar objects.

     Here is a breakdown of the NGC objects.  24 of them are galaxies, many of them very faint.  However, a small number of them are easily viewed in a 12" mirror, and should be better known by experienced viewers.  2 of the NGC located in Lyra are open clusters, including one that my object locator says does not exist (it does!).  There are two planetary nebulae, giving the famous Ring Nebula some company.  There is a single globular, an often overlooked showpiece (M 56).  The 3 IC objects are all galaxies.  For a mid-summer Milky Way constellation, Lyra has no less than 27 NGC-IC galaxies!  I was anxious and excited to locate them.  I only struck out on two, having success with the other 25!  I will continue for a few more sessions to try and locate the missing pair.  Details below.

     In this first of two blogs concerning deep sky objects in Lyra, I will discuss the non-galaxy objects.  In Part 2 I will tackle the galaxies.  

pn 6720--M 57:  This could possibly be the most famous Messier object of them all, and perhaps the most famous deep sky object of them all, too.  It is likely one of the most photographed NGC objects.  Since first seeing it with the 4.5" Tasco reflector, I have had a deep love for it.  It is stately, grand, strangely silent (it seems as if it should be accompanied by a low hum, or something similar), awe-inspiring and impressive in nearly any telescope.  Last night I observed it up to 300x in the 12", noting feathery texture on its huge surface.  I also had an opportunity to view it in a 4 1/4" Edmund Astroscan RFT reflector, at a much lower magnification.  It was tiny and certainly dimmer, but still majestic and impressive, especially with an ultrablock filter.  If a viewer is not impressed with M 57, then he is probably in the wrong hobby!   

 http://schickworld.com/Astronomy/Resized/M57-LRGBv2011S.jpg

pn 6765:  Located an easy star hop from M 56, Lyra's "other" planetary nebula is worth a look, at least with a 12" scope or larger on a dark night.  Located at 100x (15 mm eyepiece), at 67" and mag. 12.9 it is about 1/3 the size of M 57, though significantly dimmer.  At 125x (12mm) I used an ultrablock filter, getting good direct views.  Expecting a round or oval object, I was surprised to observe a slash, like an elliptical galaxy.  At times I thought I saw a central star, but this observation could not be repeated on subsequent evenings.  Located within a triangle of brighter stars (mag. 10-11), it was observed up to 200x, with better views using the filter.  The shape now reminded me of the body of an Astroscan telescope, being in two parts joined together, one of them round and larger, and the other much narrower, like a short neck protruding.  Is this a double planetary?  A puzzling but fun object to observe, and no doubt somewhat overlooked.

 http://www.ngcicproject.org/dss/n/6/n6765.jpg

     There are 3 open clusters in Lyra, 2 from the NGC, and one from Stephenson.  I will begin with the newest cluster.

oc Ste 1:  According to the newest edition of Uranometria, the area around Delta 1 and Delta 2 is now a very large and bright open cluster.  With a size of 40', use a low power eyepiece.  I loved the view with my 25 mm, giving 60x.  A dozen stars appear to be contained in a box by four brighter stars (Delta 1 is a deep, rich golden yellow), and another dozen lie outside the box.  I also viewed this at low power with the Astroscan 4 1/4", enjoying the views a lot.  The cluster is suitable for all apertures, even very small refractors.

oc 6791:  One of the best open clusters out there for larger scopes, so use at least an 8" mirror for this one.  Even the 12" does not fully resolve it, at least in my best sky.  First viewed in 1992 with the 8" scope, it took 150x back then to even begin to resolve it.  I can't wait to see this in my friend's 22" Dob!  At low power (and 12"), a large, hazy cloud of dim whiteness can be seen.  Official size varies between 10' and 20', depending on which information source is used.  I tend to go for the 20'.  There is certainly a very dense core to this cluster, but the haze spreads out beyond the main section.  At 125x it begins to resolve, and even more so at 150x.  Take your time and let your eye do its work, and very faint stars will pop out all across the object.  Think of it more like a tough globular and you will get a better idea of how to respond to it.  At 200x I enjoyed remarkable views, though there was still some haze back in there.  I observed it this year over many nights, and the cluster is a good indicator of how suitable the sky is that night for deep sky observing.  It is more difficult to resolve than many globulars, so be patient and wait for your best night.

 http://www.ngcicproject.org/dss/n/6/n6791.jpg

oc 6743:  Perhaps justifiably overlooked, nonetheless these are the objects I often enjoy tackling, for that very reason.  When I keyed in 6743 on my object locator keypad, I was informed it was non-existent.  Good thing Uranometria knows more than my keypad!  Though hardly a traditional cluster, and certainly not something you would proudly show your grandmother, the little group fits a familiar pattern for observing pros.  A bright star (mag 8) sits right in the middle of a very faint star cluster, dimming its members and hiding some, too.  Best at 150x, I counted 18 very faint stars surrounding the bright one.  I also used the cluster to star-hop to a nearby faint galaxy (eg 6740).

 http://www.ngcicproject.org/dss/n/6/n6743.jpg

gc 6779--M 56:  The final non-galaxy deep sky object in Lyra is the 2nd finest object in the constellation (oc 6791 is 3rd).  Unresolvable in a 4", the 8" used to do a pretty good job with the outliers, but not so well with stars in the core.  This is a showpiece object, often overlooked by amateurs in favour of M 13 and other more popular globular clusters.  My 12" mirror gives a remarkable view, aided by an adjacent bright star that allows perfect focusing.  Up to 200x the cluster is still bright, and resolving all across the center, which breaks into uneven segments of stars and haze, with dark lanes separating them (the 8" showed some of this, too).  I found it harder to focus at 250x, though the object was still good at this range for an experienced eye.  It is a very compact group, but its overhead sky position gives it a huge advantage over brighter and larger globulars further south on the horizon.

 http://www.ngcicproject.org/dss/n/6/n6779.jpg

     This concludes Part One of my deep sky look at Lyra.  In the next entry, I will discuss the constellation's 27 galaxies!  Stay tuned, and come back often.

Mapman Mike