May 1, 2011 Observing Report – A Taste of Discovery

There is a long record of astronomical discoveries credited to amateur astronomers.  Some have been serendipitous, while others were the result of sustained effort.  I am an experienced observer, but have no astronomical discoveries to my credit.  Although I have no burning aspiration to add my name to the list of astronomers who have discovered something new, I do apply myself seriously to the craft of observing, making sure I am accurate in recording my observations and paying particular attention to that which I cannot readily explain.

I was able to take advantage of two clear nights at Zephyr Ridge Observatory on April 29 and 30, 2011, one week after my previous report of two nights of observing there.  The vast majority of objects observed during these four nights in April were galaxies and galaxy clusters.  My recent habit in planning my observing campaigns is to print a map for each object using Voyager software.  I structure the field of view of these maps to match the field of view of my widest field eyepiece, a 26mm Televue Nagler.  In this way I am able to verify that I am observing the object on my list, and the maps also show other nearby objects that may be visible.

On the night of April 30 at 11:57 PM, I observed the galaxy NGC3982 in Ursa Major (see below for the official log).  After completing this observation, I noticed a pair of nearby galaxies on my map, NGC3972 and NGC3977, and so I took the time to observe these as well.  When I examined NGC3972, I noticed a suspicious star just off the northern side of the halo near the center of the galaxy.  This star was not shown on my Voyager map, and so I mentioned it in my log, noting that it could be a possible supernova.  Of course, there are many other possible explanations, with map error being the most common.  I have been fooled before by similar instances; in fact, on the the previous night I saw a very bright star within the halo of NGC4866 in Virgo that was also not on my map, and was so intrigued I felt compelled to check into it an hour or so later, only to discover that it was just a bright foreground star.

As it happened, I did not check on the suspicious star in NGC3972 until about a week later, when I found to my surprise that it is a supernova, SN 2011by, originally discovered on April 26, four days before my sighting!  I found out about the discovery via the internet, and here is a site that shows it on a list of recent supernova discoveries:  http://www.supernovae.net/snimages/

Zhangwei Jin and Xing Gao are credited with the discovery of SN 2011by, and I offer my congratulations to them.  Meanwhile, I am proud that I found the supernova as well, if a few days late.  My discovery was entirely accidental, and confirms that making careful notes of one’s observations is an important habit to cultivate.  My lone mistake is that I did not look into the suspicious star until much later.  What if I had chanced to observe NGC3972 during my previous trip to Zephyr Ridge Observatory the week before?  I might have seen it then, and if I had waited to check into it, I would have missed a dream opportunity to receive credit for a supernova discovery.

Visual discoveries of extragalactic supernovae are rare, and to have a reasonable chance of discovering one, observers must have a systematic plan of observation and the dedication to persist night after night.  Most are found by imaging methods these days, and some amateur astronomers are conducting automated imaging programs for this purpose, one of the better known being the Puckett Observatory effort (http://www.cometwatch.com/search.html).  I have been unable to find a precise count of the number of supernovae that have been discovered by visual methods alone.  One possible count can be made from the list of awards given for such visual discoveries by the American Association of Variable Star Observers (http://www.aavso.org/novasupernova-award).  From this list, I counted a total of 60 visual supernova discoveries since 1928, of which the majority were credited to Robert O. Evans (http://en.wikipedia.org/wiki/Robert_Evans_(astronomer)) who is undoubtedly the most famous visual supernova hunter of them all.

Perhaps some day I will join the ranks of those who systematically pursue supernovae.  For now, I take personal pleasure in knowing that I independently discovered SN 2011by, even if four days after the first discovery.  It is highly improbable that I will accidentally discover a supernova again, but I will keep my eyes open.  I hope you will do the same.  After all, you cannot win a lottery without buying a ticket.

Denis


Observations

In the remainder of this post I offer my observing notes from this latest mission to Zephyr Ridge Observatory.  I had a clear sky on both nights, albeit slightly less transparent than the very best nights out there.  Unihedron Sky Quality Meter readings averaged 21.41 on April 29 and 21.37 on April 30.

Note:  The first four observations were made with my 4” Borg refractor.  The remainder were made using my 20” Obsession reflector.

4/29/2011  10:08 PM
NGC3621 Galaxy  Hya  Mag 9.7
RA 11h18m16s  Dec -32°48’42”  Size 10’x6.5’

I used the 4″ Borg for this observation because the south wall of my observatory obstructed the Obsession.  Very low altitude view (about 11 degrees).  At 53x this galaxy was visible with direct vision, although averted vision was helpful.  It appeared as a fairly large (for this magnification) elongated hazy glow.  There were two field stars superimposed on the south side of the halo, and with averted vision I detected another star superimposed on the north side of the halo.  I did not see any central brightening.

4/29/2011  10:10 PM
M83 NGC5236 Galaxy  Hya  Mag 8
RA 13h37m00s  Dec -29°52’04”  Size 13.1’x12.2’

At 53x with the 4″ Borg, this galaxy was brighter than the previous galaxy (NGC3621) and appeared to be a face-on spiral.  It was fairly large and circular, with a brighter core area and stellar nucleus.  I did not see spiral arms, but the halo did appear mottled.  There is a flat triangle of three stars at the edge of the south side of the halo, and a fainter fourth star next to the triangle.  Again, this was a very low altitude observation (9.5 degrees).

4/29/2011  10:19 PM
NGC2251 Open Cluster  Mon  Mag 7.3
RA 06h34m42s  Dec +08°22’00”  Size 10’

I verified the location of this cluster with a map.  Using the 4″ Borg at 53x, this cluster appeared as a modest-sized, elongated collection of stars.  I resolved at least 10 stars amidst a glow of starlight suggesting a larger unresolved population.  There are two brighter stars on one side of the cluster that may or may not be actual cluster members.  Note that the cluster was only 15 degrees above the horizon during this observation.

4/29/2011  10:30 PM
NGC2324 Open Cluster  Mon  Mag. 8.4
RA 07h04m12s  Mag +01°03’00”  Size 7’

This is a very faint cluster at 53x with the 4″ Borg (at less than 15 degrees altitude).  I used a map to find the precise location, aided also by a reference to a Y-shaped asterism of seven stars that sits nearby.  I found the Y asterism, and the cluster appeared next to it.  The cluster was a very dim hazy patch and I could resolve only two stars in the midst.  I attempted to increase the power, but by the time I installed the eyepiece and refocused, the cluster had dipped below the west wall of my observatory.

4/29/2011  10:55 PM
NGC3610 Galaxy  UMa  Mag 10.8
RA 11h18m25s  Dec +58°47’11”  Size 3.2’x2.5’

(Now using 20” Obsession.) At 363x this galaxy is fairly small but bright, with a slightly elongated halo and a small, bright core.  There is a field star to the SE just off the halo, and another a little further away to the west of the galaxy.

4/29/2011  11:06 PM
NGC3631 Galaxy  UMa  Mag 10.4
RA 11h21m03s  Dec +53°10’11”  Size 4.6’

At 363x this appeared to be a face-on spiral, with a circular halo that was obviously mottled, suggesting spiral structure even though I could not explicitly see spiral arms.  The core is bright and compact, and averted vision revealed a stellar nucleus.  A very nice galaxy.

4/29/2011  11:19 PM
NGC3665 Galaxy  UMa  Mag. 11.6
RA 11h24m44s  Dec +38°45’45”  Size 3.2’x2.6’

Although the wind had picked up and jostled my scope, I was able to make a reasonable observation at 363x.  NGC3665 has a bright core and stellar nucleus.  The moderate-sized halo is slightly elongated.  A faint field star sits north of the halo.  There is a companion galaxy, NGC 3658, located to the SW, which required that I slew a short distance to see.  This galaxy is smaller and not quite as bright.  It has a prominent stellar nucleus and a circular halo.  Three bright field stars surrounded the galaxy in an approximate equilateral triangle.

4/29/2011  11:32 PM
NGC3675 Galaxy  UMa  Mag. 11
RA 11h26m08s  Dec +43°35’09”  Size 5.9’

The wind continues to buffet my scope.  At 363x this is a fine galaxy.  It is large, and has a substantially elongated halo – a nearly edge-on spiral – and the core is also elongated and had a lumpy appearance.  The halo is oriented N-S, and the east side of the halo appeared to be pinched-in, suggesting a possible dust lane.  Two field stars bracket the halo just off the southern tip, one west and one east.  Beautiful galaxy.

4/29/2011  11:42 PM
NGC3813 Galaxy  UMa  Mag 11.7
RA 11h41m18s  Dec +36°32’47”  Size 2.3’x1.2’

At 363x this galaxy appeared as an oval haze with gradual brightening towards the center.  I suspect an elongated core, but am not certain.  There is a nearby field star off the eastern tip.  Another pair was seen off the western tip.  There is also a field star just south, and another to the NNE that was a little further away.

4/29/2011  11:54 PM
NGC3877 Galaxy  UMa  Mag 12
RA 11h46m08s  Dec +47°29’41”  Size 5.4’

At 363x, this is another fine edge-on spiral.  It had a large elongated halo that appeared mottled.  The core was fairly small and averted vision revealed a stellar nucleus.  There is a bright equilateral triangle of stars NNE of the galaxy and the halo protrudes towards the center of the triangle.  Nice.

4/30/2011  12:08 AM
NGC4665 Galaxy  Vir  Mag 12.4
RA 12h45m06s  Dec +03°03’20”  Size 4.2’x3.5’

Observed at 363x.  This galaxy had a slightly elongated halo and a bright core.  I intermittently glimpsed a stellar pinpoint in the center.  There is a bright nearby field star just SW of the halo, and another bright one to the NE.  Two faint stars nearly overlap the halo on the NW.

4/30/2011 12:16 AM
NGC4697 Galaxy  Vir  Mag 9.3
RA 12h48m36s  Dec -05°48’02”  Size 6’x3.8’

At 363x, this is another fine Virgo galaxy.  It is quite bright, with a bright and slightly elongated core.  The slightly elongated halo was a diffuse glow that dissipated gradually into the background so that the boundary was uncertain.  There is nearby field star just NNW of the core.  Another is ENE of the core.

4/30/2011 12:25 AM
NGC4699 Galaxy  Vir  Mag 9.6
RA 12h49m02s  Dec -08°39’52”  Size 3.5’x2.7’

At 363x, this is a nice bright galaxy with a tiny, nearly stellar core and a small halo that was slightly elongated.  There are three nearby field stars, a faint one to the south and two to the east, the further eastward star being the brightest.

4/30/2011 12:31 AM
NGC4753 Galaxy  Vir  Mag. 9.9
RA 12h52m22s  Dec -01°11’58”  Size 5.4’x2.9’

At 363x, this galaxy is a moderately large oval, with a small core and nearly stellar nucleus.  There is a little mottling in the halo near the core, and moving away from the core the halo gradually faded into the background.  There is a field star to the west just off the halo.  A pair of stars was also seen to the NE of the galaxy.

4/30/2011 12:37 AM
NGC4781 Galaxy  Vir  Mag 12.8
RA 12h54m24s  Dec -10°32’12”  Size 3.5’x1.8’

Observed at 363x.  This galaxy is a moderate-sized elongated cloud with an irregular border.  I saw no central brightening.  There are two nearby field stars to the west, one overlapping the halo and one just off the halo, and a third field star was further away to the west.  To the SE there is a small companion galaxy, NGC4784, which had a rather small, elongated halo and a brighter core with a stellar nucleus.  NGC4784 sits in between two bright stars, one to the west and one to the north.  Returning to NGC4781 and slewing westward, I found NGC4760, which lies between two bright stars, one NE and one SW.  NGC4760, while not particularly bright, exhibited mild halo elongation and core brightening.

4/30/2011  12:48 AM
NGC4845 Galaxy  Vir  Mag 12.9
RA 12h58m01s  Dec +01°34’34”  5’x1.6’

At 363x, this galaxy is quite elongated, with a mottled halo.  There is only a little brightening of the core.  Averted vision revealed two stellar pinpoints within the galaxy, one centered in the core and one east of the core.  There is a pair of field stars just south of the halo and another star sits just north of the eastern side of the halo.

4/30/2011  12:56 AM
NGC4866 Galaxy  Vir  Mag 11.2
RA 12h59m27s  Dec +14°10’14”  Size 6.5’x1.5’

At 363x, this galaxy was very interesting.  It is an edge-on spiral with a compact core and stellar nucleus.  The halo is thin and of moderate length.  There is a bright star overlapping the halo to the west of the core, perhaps 2/3 of the way from core to western tip.  The star sits a little north of the halo’s primary axis.  This star is not shown on my map, and so I immediately wondered whether this could be a supernova.  But – alas! – later research showed the star in many photographs found online.

4/30/2011  1:05 AM
NGC4900 Galaxy  Vir  Mag 11.5
RA 13h00m39s  Dec +02°30’06”  Size 2.3’x2.2’

363x.  A moderate-sized, roughly circular cloud.  It had a tiny core that was only slightly brighter than the halo, and a stellar pinpoint was evident in the center using averted vision.  A bright field star is superimposed on the south edge of the halo.

4/30/2011  1:16 AM
NGC4958 Galaxy  Vir  Mag 10.5
RA 13h05m49s  Dec -08°01’14”  Size 4.1’x1.4’

363x.  A rather small elongated streak.  There is a bright core that was slightly elongated along the major axis.  There is a field star just to the west of the galaxy.  There is a companion galaxy, NGC4948, to the WNW and just outside the field of view with this eyepiece.  I slewed to it, and it appeared much fainter than the main galaxy, with an elongated halo and no brightening in the core area.  A pair of field stars sits to the south, just off the tip of the halo.

4/30/2011  1:22 AM
NGC4995 Galaxy  Vir  Mag 11
RA 13h09m41s  Dec -07°50’01”  Size 2.5’x1.7’

At 363x, this galaxy is a ghostly glow.  The halo is slightly elongated, and averted vision revealed a stellar nucleus without much accompanying central brightening.  There is a very bright field star just to the north of the galaxy, and a much fainter star just east of the bright star.

4/30/2011  1:30 AM
NGC5054 Galaxy  Vir  Mag 11.7
RA 13h16m58s  Dec -16°38’07”  Size 5’x3.1’

363x.  This galaxy was at low altitude and I may have been partially obstructed on the SW corner of the building.  The galaxy appeared quite dim, and seemed to be a nearly face-on spiral.  The halo is slightly elongated and mottled.  There is some central brightening in the core area, but it was subtle.  Two field stars are just off the NW edge of the halo, and two other field stars sit just east of the core and possibly overlapping the halo.  My map shows a faint companion galaxy overlapping the north edge of the halo, but I did not see it.

4/30/2011  1:39 AM
NGC5248 Galaxy  Boo  Mag 10.2
RA 13h37m32s  Dec +08°53’08”  Size 6.5’

363x. This is a nice galaxy.  It has a fairly large oval-shaped halo, with a moderately bright core that seemed a little elongated.  There is a field star within the halo NNE of the core.  The halo is mottled and suggested spiral structure, although I could not explicitly trace arms.  There is another field star just off the halo to the SSW.

4/30/2011  1:45 AM
NGC5897 Globular Cluster  Lib  Mag 9.5
RA 15h17m24s  Dec -21°00’37”  Size 11.0′

At 212x, this appeared as a fairly large, loosely organized globular cluster.  Unlike most globulars, this cluster does not have a focused core region. There is an overall large region of unresolved haziness suggesting a rich collection of stars.  I could resolve about 25 stars, approximately.  Without the expected central concentration, I would expect this cluster to have a high value for the concentration class.  I estimate 10 or 11.  (Note:  Uranometria 2000, Vol. 3, gives a value of 11.)

4/30/2011  10:37 PM
NGC3158 Group Galaxy Cluster  LMi  Mag 11.8
RA 10h13m51s  Dec +38°45’53”  Size 2.3

A little breezy, and the sky transparency seems only so-so – clear, but I have seen better nights here.  Lots of afternoon clouds may have left some moisture content.  I used a map to confirm this group and aid in the tour, performed at 363x magnification.  NGC3158 is fairly small with a bright core and small, nearly circular halo.  Moving WSW, there is a field star, and just north of the field star I saw a very faint fuzzy spot, which I identified as galaxy PGC2135428.  Extremely faint, but visible.  Returning to the main galaxy and moving directly north, there is a faint streak located just north of a field star.  This is NGC3160; it appeared as just a faint elongated streak with no apparent central brightening.  Moving west from this galaxy, I was able to detect another very faint smudge that only appeared nonstellar with averted vision.  This is NGC3152 – another extremely faint galaxy that is only barely visible and is very small; there is a field star just ENE of this fuzzy spot.  Returning to the main galaxy, I now slewed southward towards another local grouping.  I found a row of three galaxies with a field star just south of the center of the row.  The row is oriented E-W.  The westernmost galaxy, NGC3159, appeared as a small fuzzy glow that had brightening in the core.  The halo looked roughly circular.  The center galaxy, NGC3161, was a smaller circular glow with just a hint of core brightening.  The easternmost galaxy in the row, NGC3163, also appeared circular and had a stellar nucleus.  Now, I slewed slightly west of this row of three and encountered a pair of field stars whose connecting line is oriented WSW-ESE.  In between these two stars, I saw two very faint galaxies oriented roughly N-S, NGC3150 and NGC3151.  Both were barely discernable, although the southernmost, NGC3151 had some visible core brightening.  Just to the east of NGC3151, I also saw a very faint point of light that had a little fuzziness around it, which I identified as PGC2131950, an extremely faint galaxy.  This concludes my survey of this galaxy cluster.

4/30/2011  10:50 PM
Hickson 46 Galaxy Cluster  Leo  Mag 12.3
RA 10h22m02s  Dec +17°48’54”  Size 3.6’

Observed at 363x and the location was precisely determined with reference to a detailed map from Voyager software.  This grouping is at the limit of my instrument and eyes this evening.  I was able to see a row of three hazy spots, best seen by gently slewing the telescope and using averted vision.  I could see that the central member was larger than the outer two.  My map shows there are two galaxies at this central location, but I could not distinguish the two, and evidently could only see the combined light from both merged into one larger glow.  A difficult group.

4/30/2011  10:57 PM
Markarian 421 Galaxy/BL Lacertae Object  UMa  Mag 13.4
RA 11h04m27s  Dec +38°12’23”  Size 0.3’x0.23’

This blazar (blazing quasi-stellar object) is a BL Lacertae object located approximately 400 million light years away.   At 363x it was easy to find because it is located right next to two very bright stars, the brightest being 51 Ursa Majoris (mag. 6).  Markarian 421 appeared as a moderately faint field star in the presence of the glare from the two bright stellar neighbors.  I slewed the scope so that the field stars were outside of the field of view, and then Markarian 421 appeared a tiny bit fuzzy.  However, I am not certain whether this is due to my being able to see its true nature or if this fuzziness was an optical artifact from having the object so close to the edge of the field.  In any case, the blazar is certainly visible.

4/30/2011  11:09 PM
NGC3801 Group Galaxy Cluster  Leo  Mag. 12.1
RA 11h40m17s  Dec +17°43’40”  Size 3.2’

Observed at 363x.  I was able to see most of the members of this group.  The main galaxy, NGC3801, has a moderate-sized and slightly elongated halo with mild brightening in the core.  Just to the south, I saw NGC3802, an elongated streak, with the eastern tip pointing to a field star.  Moving further north, I saw an extremely faint and elusive glow that required slewing the scope and using averted vision, which I identified as NGC3803.  Continuing north and a little west, there is a pair of field stars, and proceeding further to the WNW from this pair, I was able to detect another extremely faint glow, again requiring averted vision and gently slewing the telescope to see at all; I identified this galaxy as PGC36178.  Returning to the main galaxy and slewing westward, there is a triangular asterism of three stars, and to the WNW of the brightest star in this group I saw a small galaxy with an elongated halo and a stellar nucleus.  My map shows the galaxy PGC36189 near the southernmost member of the star triangle, but I was unable to see it.  Returning to the main galaxy and slewing to the east, there is another triangular asterism of three stars, the southernmost member being quite bright.  Moving north from this asterism, I saw another extremely faint galaxy, which is barely visible with direct vision once detected.  This is NGC3807, and it appeared as a hazy spot that was a little larger than the other members of this group, with the exception of the main galaxy, NGC3801.

4/30/2011  11:22 PM
NGC3938 Galaxy  UMa  Mag 10.4
RA 11h52m49s  Dec +44°07’13”  Size 5.4’x4.9’

At 363x, this galaxy is obviously a face-on spiral.  Overall it is not particularly bright, but is easy to see.  The circular halo was mottled and had an irregular border, and there was a hint of spiral structure even though I could not clearly trace arms.  The core region was brighter and occasionally I glimpsed a stellar pinpoint in the center.  There is a field star to the SE of the galaxy.

4/30/2011  11:29 PM
NGC3941 Galaxy  UMa  Mag 11.3
RA 11h52m55s  Dec +36°59’10”  Size 3.8’x2.5’

At 363x, this galaxy had a very bright, elongated core (oval-shape).  Averted vision improved the extension of the core, making the oval even more apparent.  The halo is fairly small and also elongated.  There is a field star just off the halo to the east.

4/30/2011  11:34 PM
NGC3949 Galaxy  UMa  Mag 11
RA 11h53m42s  Dec +47°51’29”  Size 3’x1.8’

Observed at 363x.  This galaxy has an oval-shaped halo and is moderately bright.  It had only slight brightening in the core that resolves to a stellar pinpoint in the center.  Just outside the core area I saw a little mottling, suggesting dark regions in the halo right next to the core.

4/30/2011  11:45 PM
NGC3953 Galaxy  UMa  Mag 10.1
RA 11h53m49s  Dec +52°19’36”  Size 6.6’

Nice!  At 363x, this is a fairly large galaxy with an elongated halo and a bright core that was a bit elongated. Careful inspection revealed that the main axis of the core is slightly off-axis relative to the halo.  The halo is a little mottled, especially in the vicinity of the core. There are two field stars overlapping the halo near the core.  One is roughly NNE of the core, and the other is roughly west of the core.

4/30/2011  11:57 PM
NGC3982 Galaxy  UMa  Mag 11.7
RA 11h56m28s  Dec +55°07’29”  Size 2.5’x2.2’

At 363x, NGC3982 appeared as a small, roughly circular cloud with a stellar nucleus.  I saw some mottling near the core, suggesting that this could be a small face-on spiral.  There is a fairly bright pair of field stars to the south of the galaxy.  This galaxy has a couple of nearby companions to the north (requiring me to slew the scope a short distance), which fit comfortably together in the field of view of this eyepiece.  The southernmost member, NGC3972, is a fairly large elongated streak with no apparent central brightening.  There is a rather bright field star just off the center of the halo roughly to the north (in the direction of the companion galaxy) which is not shown on my map (makes me wonder – possible supernova?).  The companion galaxy, NGC3977, is a rather faint, roughly circular hazy ball with gradual and subtle brightening towards the core.

Note:  On 5/9/11 I searched online concerning NGC3972 and found that the mysterious field star just off the center of the halo to the north is indeed a supernova, discovered on April 26, 2011!  It is designated PSN J11554556+5519338 on the IAU Central Bureau for Astronomical Telegrams (http://www.cbat.eps.harvard.edu/unconf/tocp.html) and has been designated SN 2011by, as reported in the AAVSO Alert Notice 438. ( http://www.aavso.org/aavso-alert-notice-438).

5/1/2011  12:14 AM
NGC4026 Galaxy  UMa  Mag 12
RA 11h59m25s  Dec+50°57’42”  Size 5.1’

Observed at 363x.  This is a nice edge-on spiral with a bright, compact core and an extended thin halo that responded well to averted vision, which increased the extension.  There are some attractive nearby field stars. The closest is just east of the southern tip of the halo.  Some brighter stars are further south from there.  There is another field star just east of the northern tip of the halo.

5/1/2011  12:24 AM
NGC4036 Galaxy  UMa  Mag 10.6
RA 12h01m27s  Dec +61°53’44”  Size 4.5’

At 363x, this is another nice edge-on spiral with a bright core and stellar nucleus.  The halo was moderate-sized, but did not extend quite as far as the previous galaxy I observed (NGC4026).  After careful study, I suspect a possible dust lane on the south edge along the main axis, where it looked a little pinched-in, especially near the core.  It’s subtle, and so I am not certain of this assessment.

5/1/2011  12:29 AM
NGC4041 Galaxy  UMa  Mag 11.2
RA 12h02m12s  Dec +62°08’15”  Size 2.8’x2.7’

Observed at 363x.  This galaxy is located just NNE of NGC4036, observed just before.  NGC4041 has a small, circular halo that diffuses gradually into the background.  There is gradual brightening towards the core and I would assess the core as rather large.  There is a field star off the halo to the NE.

5/1/2011  12:41 AM
NGC4102 Galaxy  UMa  Mag 11.8
RA 12h06m23s  Dec +52°42’39”  Size 3.2’x1.9’

At 363x, this is an interesting galaxy.  It is of modest size and had an oval-shaped core with a stellar nucleus.  The halo is also elongated, and the long axis is oriented SW to NE.  The SW side of the halo seemed more disturbed, especially more towards the south.  It seemed more mottled/broken-up in that direction.  On the SW edge of the halo there is a bright field star.  Just off the NE end is another field star, which is not quite as bright and a little further away from the galaxy.

5/1/2011  12:48 AM
NGC4005 Galaxy Cluster  Leo  Mag 14
RA 11h58m10s  Dec +25°07’19”

I toured this group at 363x.  This group is anchored by a very bright star (HD103913, mag. 8.27), and the main galaxy, NGC4005, is SE of that star and immediately south of a much fainter field star.  NGC4005 is not particularly bright, although easy to see, with an oval halo and mild central brightening.  Returning to the bright star and moving westward, I saw NGC4000, which is a very faint elongated streak.  Now I slewed back to the SE to located NGC4011 (ESE of NGC4005 by my map), but after careful inspection, I was unable to see it (Voyager software gives it mag. 15.75).  So, I slewed past these, continuing SE and found NGC4015 and NGC4023NGC4015 is faint, although conspicuous, with a roughly circular halo, and mild core brightening with a stellar nucleus.  NGC4023 is smaller and elongated, with no central brightening.  At this point exhaustion and irritability stopped my progress, as I was perched in an awkward position on the ladder and my controlling hand was getting frozen!  So, I stopped here, even though other galaxies remained according to my map.

About Denis

I am the owner of Zephyr Ridge Observatory and the writer of this blog. For more information, please click the About link at the top of this page.
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