Galaxy of the Month in Coma Berenices

• NGC 4278 in Coma Berenices

  May 2025 - Galaxy of the Month

  As the brightening skies of May approach, I have chosen for the galaxy of the month the trio of galaxies in Coma Berenices, NGC 4278, NGC 4283 and NGC 4286. All three of these galaxies were discovered by William Herschel in 1785.

  NGC 4278 is the brightest of the trio and is an elliptical galaxy classified as E1-2. It contains an AGN of the LINER type. A small pair of weak radio jets have been found in the galaxy as well as it having a strong and variable UV source at its centre. This flaring variability also extends to the X-Ray output from the galaxy. The radio jets also appear to be associated with high energy gamma ray emission from the galaxy. Images with the Hubble space telescope also show a lot of dust features near the nucleus which is unusual for an elliptical galaxy. The galaxy is also surrounded by a larger number of globular clusters than expected. NGC 4278 is thought to be about 55 million light-years away.

  NGC 4283 is also an elliptical galaxy classified as E0. NGC 4286 is probably a lenticular galaxy, but has also been classified as a dwarf galaxy, and it does show a lot of emission in the UV which suggests a lot of star formation going on.

  In fact, given the distance all the galaxies here are quite small with the largest, NGC 4278, probably only about 65,000 light-years across, so about half the size of our Milky Way. The group are probably physically associated and have the designation 399 in the WBL catalogue. The group are suspected to be part of one of the filaments associated with Virgo cluster.

  It is also suggested that NGC 4278 is part of a galaxy group associated with NGC 4274, although there is some debate on that. It is also part of the Coma I group of the Virgo cluster. NGC 4274 lies about 20’ to the north of NGC 4278.

  NGC 4278 is a part of the Astronomical League's H400 list and at around 11^th magnitude should be visible in quite small telescopes. NGC 4283 is much fainter at around 13^th magnitude so should be more of a challenge for larger telescopes. NGC 4286 is fainter still at around 14^th magnitude so will require a much larger telescope to find unless you have access to very dark skies.

  It does help that the brighter two galaxies are ellipticals with bright cores so should be easy to spot. NGC 4286 is an edge on galaxy so it will be harder to see. The group is however quite tight and will fit in the same field of view using a modern hyperwide field eyepiece at high power, which may be the best way to catch NGC 4286. The Night Sky Observer's Guide Vol 2 suggests that in a 35cm telescope NGC 4286 is a difficult faint smudge. The other two should be visible in 25cm telescopes. The galaxy also makes The Cambridge Photographic Atlas of Galaxies.

  Owen Brazell - Galaxy Section Director

• NGC 4298 in Coma Berenices

  April 2022 - Galaxy of the Month

  Our galaxy of the month this month is the nice galaxy pair in Coma, NGC 4298 and NGC 4302, both of whom were discovered by William Herschel in 1784. They are both spiral galaxies with NGC 4298 being almost face on and NGC 4302 being edge on.

  Although they lie in the constellation of Coma they are actually part of the Virgo cluster lying at a distance of perhaps 55 million light-years away. At this distance the core-to-core distance between the pair is thought to be only about 35000 light-years but they don’t seem to be showing any signs of interaction, at least in the visual part of the spectrum. There is, however, a tidal bridge that was discovered in the radio spectrum using the line of neutral hydrogen (HI).

  NGC 4302 is also suspected to be a Seyfert or LINER type galaxy with an AGN. NGC 4302 also sports a tidal tail that is likely due to the RAM pressure from the intracluster gas as it falls into the Virgo cluster. The boxy nature of the nucleus of NGC 4302 also suggests that it may have a bar, however this would not fit with its Sc classification (it would be SBc in that case).

  NGC 4298 shows numerous star forming regions in ultraviolet images taken with the GALEX satellite. Its classification is SA(rs)c, although it is also classified as a flocculent spiral.

  There is a glorious image of the pair taken as part of the 27th anniversary of the launch of Hubble. Here NGC 4302 looks a little like the brighter NGC 891. NGC 4302 does show a single very bright blue star forming region that is very prominent in the UV images. There may be others that are hidden behind its dust lane. They are both somewhat smaller than our Milky Way galaxy. The pair is also known as Holmberg 377.

  The two galaxies are so close together that they will fit in a high power field of view and this maybe the best way to look at them.

  NGC 4298 and NGC 4302 both make it into Night Sky Observer's Guide (NSOG) Vol. 2 where it suggests they are targets for 20-25cm telescopes. I suspect this may not be the case if you live in the UK. NGC 4298 and 4302 both make it into the Herschel II observing list from the Astronomical League. The pair also made the DeepSkyForum.com Object of the Week (OOTW) in 2015. It seems that to see the dust lane in NGC 4302 requires a very large telescope from those reports. The pair are listed, although not described, in Burnham's Celestial Handbook and makes multiple Texas Star Party (TSP) observing lists.

  If you find this pair too easy then try for the 15th magnitude galaxy MCG 3-32-12 nearby, it should fit in the same medium power field as the main pair.

  Owen Brazell - Galaxy Section Director

• NGC 4065 Group in Coma Berenices

  April 2018 - Galaxy of the Month

  This group of 9 NGC galaxies in Coma is an extremely confusing field as some of the galaxies seem to have been observed by William Herschel and then later by John Herschel but given the wrong positions. They were then added into the NGC as separate objects. This has led to a great deal of confusion and to various designation issues.

  The main issues seem to surround the galaxies numbered as NGC 4055, NGC 4057 and NGC 4059 discovered by John Herschel. These are probably the same galaxies discovered by his father and catalogued as NGC 4061, NGC 4065 and NGC 4070 respectively.

  The situation was then further complicated by Marth who, when observing with Lassell’s 48” in Malta, found two more galaxies in this group. Unfortunately the positions that Marth gave were very uncertain so it is difficult to ascertain which NGC number belongs to which galaxy of those he discovered.

  And then there is NGC 4069, another of the galaxies discovered by John Herschel but difficult to tie down to an actual galaxy with any certainty. The situation is further complicated by the fact that the designation NGC 4057 is sometimes given to a completely different galaxy.

  The confusion over these galaxy names is amply illustrated by the two finder charts attached, one from Sky Tools that adopts one of the numbering systems and one from Megastar which adopts the other. The mess around the numbering of these objects is discussed in Harold Corwin’s NGC notes.

  NED appears to adopt the primacy of the NGC 4065 system. If we adopt that numbering system then the NGC 4065/4061 pair is also an interacting pair numbered VV 179. Most of the galaxies in the group are ellipticals with the exception of NGC 4072 which is a spiral.

  The whole group is listed in the WBL catalogue of poor galaxy clusters as WBL 374 which is listed as containing 19 galaxies, including the NGC galaxies 4061, 4060, 4065, 4066, 4070, 4072, 4076, 4074, 4086, 4090, 4089, 4091, 4092, 4093, 4095 and 4098. If this is correct the group would contain two sub groups centred around the galaxies NGC 4057 and NGC 4095, separated by perhaps 30’. Unfortunately the designation issues in the second sub group around NGC 4095 are just as messy as in the first.

  NGC 4098 would also appear to be an interacting system and is catalogued as VV 61. It would be interesting to know what power and size of telescope is required to split this system as the SDSS image shows a second galaxy much closer in along with the disturbed spiral arms of the main galaxy. As the separation between the galaxies is only about 10” it is likely to require high power and good seeing.

  The distance to this group is probably of the order of 100 Mpc. The magnitudes of these galaxies suggest that to adequately explore the group, certainly from typical UK skies, will require a telescope of at least 40cm aperture and probably more.

  

  Andrew Robertson when using his 24” telescope drew not only the NGC galaxies in the 4057 subgroup but also managed to pick up one of the UGC ones as well. Unfortunately at the time he did not know about the rest of the group so was not able to get the others.

  Owen Brazell - Galaxy Section Director

• March 2014 - Galaxy of the Month

  M99 in Coma Berenices

  

  Image Courtesy of Warren Keller, New Mexico. Please click on image for a high resolution version.

  M99 hit the news recently because it had the second supernova this year found in a Messier galaxy, the first being M82. The supernova in this case never got that bright reaching only about 14th magnitude at maximum. First discovered by Pierre Mechain in 1781 it was added to Messier's last instalment of his catalogue of Nebulae and clusters. It is one of the faintest of the Messier objects and this is not helped by it being a face on spiral. It became famous as the second galaxy that Lord Rosse observed to have a spiral shape after M51 in 1846. Messier 99 is a standard grand design Spiral galaxy located at about 50 million light years from us. This has led to a morphological classification of SA(s)c. Although situated in the constellation of Coma M99 is actually part of the Virgo cluster, although there are some suspicions that it may be entering the cluster for the first time and is subject to some ram pressure stripping. Messier 99 does have the highest recession velocity of all the Messier galaxies. The galaxy also appears to have star formation going on at perhaps three times the expected rate for a galaxy of this time which could have been triggered by the interaction. This may account for the supernova. There have been three supernovae identified in M99 in the last century. There also appears to be a stream of gas linking it to the dark galaxy VIRGOHI21. This object appears to be a cloud of neutral hydrogen gas (HI) but its internal motions suggest that it may contain a lot of dark matter. However there are also some theories that suggest that this cloud is merely part of the tidal tail from M99. It is also possible that the distorting galaxy may be the lenticular galaxy NGC 4262. If this was the case then the encounter happened maybe 280 million years ago. Although not shown on our image the chart shows the location of NGC 4262 in relation to M99. A close up of M99 taken by the HST can be found here.

  A nice sketch of the galaxy can be found on the ASOD website, as can a sketch of the galaxy with the supernova. The image also shows the lovely coloured double star HJ 207 – one of John Herschel’s discoveries.

  The Megastar© finder chart shows the M99 region.

  Owen Brazell - Galaxy Section Director

• May 2013 - Galaxy of the Month

  NGC 4565 - The Needle Galaxy in Coma Berenices

  

  Image Courtesy of Ken Crawford, Camino, California. For more images from Ken please visit his Rancho Del Sol Observatory website. You can click on image for a high resolution version, or download a copy of our Megastar© finder chart of NGC 4565.

  NGC 4565 was first discovered by the prolific William Herschel in 1785 and is an edge on spiral galaxy also known as the Needle galaxy. There is some debate as to the actual type of spiral but it is thought probably to be a barred spiral. Recent observations with the Spitzer infra-red satellite and radio observations appear to confirm this classification.

  NGC 4565 is at a distance of about 11.7 Mpc (about 40 million light years) and at that distance would have a size of about 100,000 light years (not dissimilar to our own Milky Way).

  The box like nucleus is however interesting and it would appear to be interacting with one of its neighbours. This may not be NGC 4562 as that galaxy appears to be at a distance of 12.6 Mpc which is a bit further away (probably about the distance to M31 from our own galaxy), so although they may be a bound pair it is unlikely it is stirring much in the way of tides.

  NGC 4565 also appears to be an AGN with there being some confusion over whether it is a Seyfert or a LINER. NGC 4565 is often used as an example of what our own Milky Way galaxy would be like if seen from the outside, however our galaxy is certainly not (at this time) an active galaxy. It is thought that NGC 4565 has about 240 globular clusters surrounding it, somewhat more than the Milky Way.

  The area around NGC 4565 is littered with faint galaxies. Many of these were found photographically by Max Wolf and appear in the IC catalogue. The brightest of NGC 4565 companions is NGC 4562 (sometimes called NGC 4565A), however at around 14th magnitude this galaxy is still quite a challenge to find. It was first discovered by Tempel in 1882 with an 11" Refractor. It would appear that many of the IC galaxies discovered by Wolf are random background galaxies and are not associated with NGC 4565. The brightest of these is IC3546 (also known as NGC 4565B from the RNGC).

  Off the end of NGC 4565 is a very distant cluster of galaxies that is too faint to have been in George Abell’s catalogue but shows up in deep images.

  NGC 4565 is also one of the brightest members of the Coma I galaxy cloud, a collection of perhaps 206 galaxies. The fast motions of the galaxies in this area maybe a case for a dark attractor.

  It is odd that such a bright galaxy that is visible in small telescopes and even in some cases binoculars was missed by Messier but it shows how inhomogeneous his searches were. NGC 4565 is probably one of the finest non Messier objects in the sky and shows much in almost any sized telescope and the prominent dark lane is visible with telescopes of maybe 20cm and above.

  Owen Brazell - Galaxy Section Director