Galaxy of the Month Archive 2022

In this series of articles we draw your attention to galaxies particularly worthly of an observer's time.

• NGC 533 in Cetus

  December 2022 - Galaxy of the Month

  This month’s challenge is the galaxy pair in Cetus including NGC 533 and NGC 521. There is also a third galaxy in the field in IC 1694. NGC 521 and NGC 533 were discovered by William Herschel in 1785. IC 1694 was discovered in 1891 by Bigourdan using a 12.4” refractor. The group will best be seen in the early evening this month.

  The RC 1 suggested that NGC 521 and NGC 533 form a physical pair, however they do not appear to be interacting and their distances do appear to be somewhat different. NGC 533 is described as an elliptical galaxy with a classification of E3. It is also classified as a cD galaxy, which would be the brightest and largest galaxy in a cluster. NGC 521 is a face on low surface brightness spiral, classified as SB(r)bc. The GALEX images in the UV indicate the NGC 521 is undergoing a lot of star formation in its spiral arms.

  Interestingly NGC 533 is suggested to be part of the galaxy cluster Abell 189 although NGC 521 which is in a pair with it is not, although they are very much brighter than the other galaxies in the cluster and somewhat offset from it. The distances for NGC 521 and 533 are also very different so it may be that they are just an optical pair. NGC 533 Is also surrounded by many faint galaxies. The cluster ACO 189 is also much further away than either of the NGC galaxies. NGC 521 lies at a distance of perhaps 34 Mpc whilst NGC 533 would appear to be almost twice as far away at perhaps 70Mpc.

  NGC 521 has produced 3 supernovae since 1966.

  IC 1684 is also suggested to be part of Abell 189 and thus associated with the NGC 533/521 pair, however although it is not well studied its distance lies at around 50 Mpc so in these terms at least it would not be associated with either ACO 189 or the other two galaxies. All in all this is quite a confused field and it may be that none of the galaxies are associated.

  Perhaps surprisingly Night Sky Observer's Guide (NSOG) Vol.1 suggests that much can be seen of this pair with telescopes in the 20-25cm aperture. However, to see IC 1694 will require telescopes in the 45-50cm range. I suspect that many of the observations used in the NSOG may have been from high altitude, and from the poorer skies of the UK 30cm may be required to see much. All three galaxies are close enough together that they will fit in the field of view of a medium power hyperwide eyepiece. To find IC 1694 however is likely to require a high power. The much fainter galaxies around NGC 533 are probably out of visual range but should be picked up by EAA systems.

  Owen Brazell - Galaxy Section Director

• NGC 7469 in Pegasus

  November 2022 - Galaxy of the Month

  Our challenge this month is the tight galaxy pair in Pegasus catalogued as NGC 7469 or Arp 298. Arp included the pair as part of his double galaxies classification. The brighter of the pair, NGC 7469, was discovered by William Herschel in 1784. The other galaxy in the pair, IC 5283, was found by Bigourdan in 1891 using a 12.4” refractor.

  Both galaxies are spirals with NGC 7469 being a barred spiral hosting an AGN of the Seyfert I type. NGC 7469 was one of the 6 galaxies that Carl Seyfert included in his original 1943 paper on Type I Seyfert galaxies. It is also a luminous infrared source (LIRG) with the source powered by a starburst in a circumnuclear ring.

  The two galaxies are gravitationally interacting and the interaction appears to have pulled a tidal tail from IC 5283 and also initiated a strong burst of star formation in IC 5283. The interaction may also be the cause of the starburst in NGC 7469. The UV images from GALEX show strong star forming activity in both galaxies and this may be the reason it was included by Markarian in his blue galaxies catalogue. There also appears the be a neutral hydrogen bridge (HI) between the two galaxies.

  The pair lies about 200 million light-years away. If they are at this distance then NGC 7469 will be about the same size as our Milky Way galaxy. The galaxies appear to be an isolated pair, i.e. not part of any galaxy group. There was some thought that they might be part of the Pegasus I galaxy group but they have been shown to lie much further away than that group.

  The pair were selected to be one of the first targets for the James Webb Space Telescope (JWST). There is also a nice Hubble image of the pair on the ESA/Hubble website.

  Two supernovae have been recently found in NGC 7469: SN 2000ft and SN 2008ec (type Ia).

  As this galaxy pair is so close together it is going to require high power to separate them. NGC 7469 itself should be fairly easy to see but IC 5283 is much fainter at around 14.8th magnitude so it is going to require a large telescope to find. It is also an edge on galaxy that will make seeing it even harder.

  The Night Sky Observer's Guide Vol. 1 suggests that 30cm may be needed to see NGC 7469 and 45cm to see IC 5283 which will appear as not much more than a faint oval patch. The pair do lie in a pretty star field however. Alvin Huey’s observations suggested that with a 55cm (22”) telescope NGC 7469 is very bright but IC 5283 is still no more than a faint streak.

  Owen Brazell - Galaxy Section Director

• NGC 470 in Pisces

  October 2022 - Galaxy of the Month

  Our galaxy of the month this month is the tight triplet of galaxies in Pisces around NGC 470. I must thank Mark Stuart for recommending this group to me. The triplet includes NGC 467, NGC 470 and NGC 474. All three galaxies were found by William Herschel. NGC 470 and NGC 474 in 1784 and then NGC 467 a year later in 1785.

  NGC 470 is a disturbed system and was included by Vorontosv-Velyaminov as number 948 in his extended catalogue. NGC 474 is also a disturbed system and Arp included it as Arp 227. It is not clear whether Arp meant Arp 227 to include both NGC 470 and NGC 474, or just NGC 474.

  Arp 227 is a shell galaxy and appears to be in a physical pair with NGC 470. The pair lie at about 100 million light-years from us. NGC 467 is also a shell galaxy but is much further away than the others, although some older sources do suggest it is gravitationally part of the NGC 474 group. NGC 467 is also suggested to be a lenticular galaxy.

  Shell galaxies are relatively rare, with maybe 10-20% of galaxies in this class, so to get two in the same field is unusual. Shell galaxies come about when another galaxy has been digested and the stars thrown out from the interaction form these shells. It would appear that NGC 474 ingested a spiral galaxy in two phases, the first pass being about 1.3 billion years ago and the final pass about 900,000 million years ago. It is not clear if NGC 470 is gravitationally interacting with NGC 474 as well.

  NGC 470 has some very chunky spiral arms and there are some suggestions of plumes in deep images. NGC 470 shows up strongly in the GALEX UV images which suggests that there is a lot of star formation going on in it. The other two galaxies barely register in the UV.

  Hubble took a nice image of NGC 474. NGC 474 would appear to be about 2.5 times the size of our Milky Way at about 250,000 light-years across. There is also a Canada France Hawaii Telescope (CFHT) image of both NGC 470 and NGC 474. NGC 474 seems to be catalogued as a lenticular galaxy, although there were suggestions that it may be an elliptical.

  The galaxy trio is pretty tight so all the galaxies will fit in the same field in a modern hyperwide eyepiece at medium to high power. The presence however of the 8th magnitude star HD7991 in the field may make finding NGC 467 more difficult than it might be. The Night Sky Observer's Guide (NSOG) Volume 1 suggests the whole group should be visible in 20-25cm telescopes but recommends 30-35cm for this. The NSOG also suggests that NGC 470 and NGC 474 have very bright nuclei but the rest of the galaxies are rather faint. Given the poorer skies of the UK I suspect that 40cm may be required to see much.

  Owen Brazell - Galaxy Section Director

• NGC 7771 Trio in Pegasus

  September 2022 - Galaxy of the Month

  For the September GOM I have chosen the tight galaxy trio in Pegasus around NGC 7771.

  There are three NGC galaxies in the trio, NGC 7769, NGC 7770 and NGC 7771. All three of the galaxies were discovered on the same night by William Herschel in September 1784. For EAA observers there are two much fainter galaxies in the same field. The three galaxies appear to form a physical group along with LEDA 214993, also known as NGC 7771a. They are also classified as Holmberg 820. They also make it into both the WBL (726) and LGG (483) galaxy group catalogues.

  Both NGC 7770 and NGC 7771 appear to be slightly distorted from a gravitational interaction. All three appear to be spiral galaxies with all of them appearing to have a lot of star formation going on from the brightness in the UV images from GALEX. NGC 7771 is also classified as a luminous infrared galaxy (LIRG) starburst which also suggests that a lot of star formation going on is hidden by dust. It will be interesting to see if Webb images it as Hubble used its near infra-red camera to get an image of the centre of NGC 7771.

  The distance to the group is thought to be about 60Mpc. The group appears to have been interacting for some time as there are numerous star streams in the group. Over cosmic time all three galaxies are likely to merge. It is not clear if NGC 7771a is part of the triplet as there is very little hard information on it. Unfortunately deep images of the group are complicated by the presence of dust (IFN) in our own galaxy in front of the group, although there is a fine amateur image of the group by Capella observatory showing some of the interaction details. Despite the group not make the Arp atlas it is added as VV 2003 in the revised Vorontsov-Velyaminov catalogue, although this may only apply to NGC 7770.

  The Type II supernova SN2022mxv was discovered in NGC 7769 but only reached maybe 15th magnitude. NGC 7769 is also suspected to be a LINER, a weak form of AGN.

  The Night Sky Observer's Guide (NSOG) Vol. 1 suggests that to see the whole group then you will require a telescope in the 40-45cm class and even then NGC 7770 will only appear as a faint smudge. The brightest galaxy in the Trio is actually NGC 7769 so that should be the easiest to find. As the group is so tight it will be worth using the highest power you can get away with to separate them and to increase the contrast to see NGC 7770.

  The group also makes it into the Cambridge Photographic Atlas of Galaxies. They are also included in Alvin Huey’s guide to Galaxy Trios as well as Miles Paul’s Atlas of Galaxy Trios, downloadable from the Webb Society website. The group has been included in the Herschel 300 list, an extension to the better known H400 and H400 II list.

  Owen Brazell - Galaxy Section Director

• NGC 315 in Pisces

  August 2022 - Galaxy of the Month

  For the August galaxy of the month I have chosen NGC 315 in Pisces. Although perhaps a bit early for galaxies in Pisces, we are still in Milky Way season. NGC 315 was discovered by William Herschel in 1784. It appears to be part of a small group on the sky that also contains NGC 311 and NGC 318.

  NGC 315 contains an AGN, in this case a LINER, with a well collimated radio jet coming from the central black hole. The jet has also been detected in X-Rays. The jet appears as two main parts, a bright main jet and a smaller counter jet. The mass of the central black hole has been calculated to be of the order of 2x10⁹ solar masses from observations of cold molecular gas around it using ALMA. The nucleus also shows up well in the UV images from the GALEX satellite.

  There may be upwards of 30 galaxies in the group associated with NGC 315. NGC 315 is part of Zwicky cluster 0107.5+3212 (Zwicky et al. 1961), which is located in the Perseus-Pisces filament. It is also part of the group WBL 22 (which only contains NGC 311, NGC 315 and NGC 318) and LGG 14 (which contains many more). NGC 315 is classified as a cD elliptical galaxy; these are large elliptical galaxies found at the core of clusters. The group is thought to be at a distance of perhaps 55 Mpc. Most studies of this galaxy seem to concentrate on the jet.

  Observationally NGC 315 is defined to be part of a trio of galaxies including NGC 311 and NGC 318. NGC 311 and 318 are much fainter than NGC 315. NGC 311 was discovered by John Herschel in 1828 and NGC 318 by Bindon Stoney using Lord Rosse’s 72” telescope in 1850. They both appear to be lenticular type systems. Stoney also thought he discovered another two galaxies in the field that got the NGC numbers NGC 313 and NGC 316 but it turns out these were just stars.

  Night Sky Observer's Guide (NSOG) suggests that all three can be seen with a 35cm telescope, although NGC 318 is recorded as difficult to see. My suspicion however is that these observations were made from high altitude sites and from the UK it may require 40cm to see all three given the extra mile of crud above most UK observing sites. The group is a very tight one and will easily fit in a high power eyepiece field. Observations of the group maybe complicated by an 8th magnitude star close by in the field. NGC 315 is included as part of the Astronomical League H400 II list.

  Owen Brazell - Galaxy Section Director

• NGC 6384 in Ophiuchus

  July 2022 - Galaxy of the Month

  I must admit that every summer I ask myself if it is worth doing a GOM for the months of June and July as it never gets dark in the northern latitudes of the UK, and this year (2022) even if it had got dark we seem to have had perennial cloud cover, except of course during the full moon period! However just to keep the sequence running I have chosen the galaxy NGC 6384 in the northern part of Ophiuchus as this month’s challenge.

  Much to my surprise Ophiuchus is littered with faint galaxies with maybe 9 from the NGC catalogue alone. NGC 6384 is a bright galaxy that was missed by William Herschel and was subsequently discovered by Marth in 1866 from Malta using William Lassell’s 48” speculum metal mirror telescope and then independently by d’Arrest and Stephan a few years later. Marth described it as pretty bright.

  The bright nuclear region, which is all that I suspect most people will see, is because the object is a LINER, a form of low luminosity AGN. It is regarded as a weakly barred system about 80 million light-years from us and was host to SN 1971L, which despite occurring in the spiral arms was probably a type Ia. It was also home to SN 2017drh. If it is at this distance then it is perhaps 150,000 light-years across, so slightly larger than our own Milky Way galaxy. NGC 6384 is regarded as probably very similar to what our Milky Way might look like. Hubble imaged the central core of this galaxy in 2011. NGC 6384 appears to be a field galaxy, not associated with any others. GALEX images in the UV part of the spectrum show that NGC 6384’s spiral arms are marked out by very active star forming regions which indicate that the galaxy is currently undergoing a lot of star formation. There is also a fine amateur image at the Capella Observatory.

  Luginbuhl & Skiff (L&S) suggest that NGC 6384 is barely visible in 15cm and shows as a faint patch in 25cm, remember however these observations were from a high dry site so don’t expect to see much with such a small telescope from the UK. The Night Sky Observer's Guide (NSOG) Vol. 2 has NGC 6384 covered as the only galaxy in Ophiuchus. It again suggests that 25cm telescopes should show the core and 40-50cm will show a faint haze surrounding a bright core but are not going to show any spiral structure. Steve Gottlieb notes that there is some structure in the outer haze as seen with his 24”. Observations from the UK with a 35cm suggest that it is not too impressive and only the core is seen. NGC 6384 also has an entry in The Cambridge Photographic Atlas of Galaxies.

  Owen Brazell - Galaxy Section Director

• NGC 5921 in Serpens Caput

  June 2021 - Galaxy of the Month

  June at the latitude of the UK has to be one of the worst two months for galaxy observing, at least visually, as we do not get astronomical dark until mid-August again. As such any object for the GOM has to be brighter than the usual case.

  My choice this month is the 11th magnitude galaxy NGC 5921 in Serpens Caput. NGC 5921 was discovered by William Herschel in 1786. Mitchell using Lord Rosse’s 72” at Birr suggested that it showed spiral structure, although it does not seem to have been added to their list of spiral galaxies.

  NGC 5921 is a barred spiral classified as SBbc, although it has also been classified as SB(r)bc, which suggests that the spiral arms may start from a circumnuclear ring. In this case the spiral arms start from the end of the bar but appear to form a ring afterwards. The galaxy has a small bright nucleus with open spiral arms containing a lot of HII regions. The central bar does appear to have a prominent dust lane across it. Interestingly the form of the galaxy depends on what wavelength it is photographed in and only the blue images show spiral structure. The red image just show dust.

  The distance measurements seem uncertain and vary between 65 and 80 million light-years. Hubble has imaged the galaxy. There is also a superb amateur image of it by Adam Block. NGC 5921 does appear to contain a supermassive black hole at its centre. If this is the case the galaxy may also be a mild form of AGN known as a LINER.

  Unusually NGC 5921 does not appear to be a part of any galaxy group and is a field galaxy. It was home to the Type II supernova 2001x. If the longer distance computations are right then NGC 5921 is a relatively large galaxy at about 100,000 light-years across, about the size of our own Milky Way.

  Interestingly the Night Sky Observer's Guide (NSOG) Vol. 2 suggested that you need a 30cm telescope to see it and then it only shows the bright core and a faint haze. NSOG suggests that a 40-45 cm telescope should show some detail in the haze. Observations from the UK suggest that the core at least can be seen in 25cm from moderately dark skies. NGC 5921 is also featured in The Cambridge Photographic Atlas of Galaxies. For those that like working from lists, NGC 5921 is included in the Herschel 3 list: a list of 300 galaxies after the H400 and H400 part II from the Astronomical League.

  Owen Brazell - Galaxy Section Director

• NGC 4754 in Virgo

  May 2022 - Galaxy of the Month

  With the skies from northern latitudes starting to brighten at this time of year making galaxy observing more difficult I have to start choosing brighter objects for the GOM.

  Our galaxy this month is the nice pair in Virgo of NGC 4754 and NGC 4762. They were both discovered by William Herschel on the same night in March 1784. They are also known as Holmberg 478. NGC 4754 is also classified as an interacting system as VV 1573 in the extended Vorontsov-Velyaminov catalogue. Although Virgo is now starting to slip away from the observing season, and the nights are getting bright now in May, it should still be possible to pick up this pair.

  Both are suggested to be lenticular galaxies with a classification of SB0 which suggests a barred form. They present quite different projections on the sky however with NGC 4762 being practically edge on and NGC 4754 being more open.

  The galaxies are suggested to be a non-interacting pair, although both galaxies do show some signs of interaction, particularly NGC 4762 which shows tidal distortions at both ends of the galaxy in deep images. The problems come in that the distance measurements to each galaxy would suggest they are not close together in space, however the distance measurements by differing methods are wildly discordant. They are both however believed to be members of the Virgo cluster. There are suggestions that NGC 4762’s extensions may have come from a merger with a smaller galaxy a few billion years ago. NGC 4762 also appears to have a form of AGN, classified as a LINER. If the distances are correct these are both very large galaxies, slightly larger than our Milky Way.

  Stephen O’Meara in his book The Secret Deep suggests that Allan Sandage noted that NGC 4762 is one of the flattest galaxies, as seen from the earth, in the universe. He also nicknames it the Paper Kite galaxy based on a description in Smyth’s Bedford catalogue. Both galaxies appear in the Astronomical League’s H400 program and, indeed, in many other lists. There is a stunning amateur image of the pair at the Capella Observatory website. NGC 4762 was also imaged by the Hubble Space Telescope (HST).

  One of Lord Rosse’s assistants, Samuel Hunter, suggested that he could see that NGC 4762 was warped with the 72” at Birr. It is probable that with the larger aperture telescopes now in amateur hands that these may also be visible today. Night Sky Observer's Guide (NSOG) Vol.2 suggests that 20-25cm telescopes will be needed to see both galaxies and that 40-45cm should start showing some detail. I suspect that given the usual skies from the UK then perhaps 30cm maybe better for seeing them, although there are observations of NGC 4754 at least with a 25cm scope from less than ideal skies in the UK. There are also observations of NGC 4762 in the Webb Deep-Sky Society Observer's Handbook (WSDSOH) Vol 4, but perhaps surprisingly not NGC 4754. Luginbuhl and Skiff (L&S) suggests both galaxies are visible in 15cm, but remember their observations were done from high and dry altitude sites. They do suggest however larger apertures to see any detail.

  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

• Abell 1185 in Ursa Major

  March 2022 - Galaxy of the Month

  This month’s challenge is the often-overlooked galaxy cluster Abell 1185 in Ursa Major. Perhaps not unsurprisingly it was covered 40 years ago in the Webb Deep-Sky Society Observer's Handbook (WSDSOH) Volume 5.

  The core of the group contains 6 galaxies listed in the NGC, with the brightest being NGC 3350. NGC 3350 was discovered by William Herschel in 1785. Herschel also found NGC 3552, along with an outlier to the main group in NGC 3527 at the same time. John Herschel found NGC 3554 along with 3561 whilst revisiting his father’s observations. Heinrich d’Arrest found NGC 3558 in 1866. The sixth is classified as NGC 3561A.

  The cluster is thought to be about 400 million light-years from us and perhaps 1 million light-years in width. It does feature in a Hubble image at ESA/NASA website. Here you are of course just viewing the very centre of the cluster. There is also a wider field view of the cluster. Abell 1185 is thought to be a member of the Leo Supercluster and is the brightest member of that grouping. The suggestion is that the cluster contains at least 85 galaxies and has an Abell richness class of 1, i.e. not very rich 😊

  The cluster seems to contain a large number of interacting galaxies with two appearing in the Vorontsov-Velyaminov (VV) catalogue with NGC 3561 being VV 237 and NGC 3530 being VV 1419. The cluster also contains Ambartsumian’s knot (a dwarf galaxy at the end of the banjo like tidal feature associated with NGC 3561A, also known as Arp 105). This feature is also known as the Guitar. NGC 3561 also contains a weak AGN of the LINER type. The group does seem to contain quite a few spirals and perhaps lenticulars which suggests it is quite a young cluster still coming together. There are also various sub clumps within the cluster which supports this theory. Abell 1185 also seems to be home to a large number of wandering globular star clusters that are not attached to any galaxy.

  The cluster is a very compact one with all the major NGC galaxies fitting in the same field in a high power (345x) modern hyperwide eyepiece. This will probably be the best way to see them as the individual galaxies are not that bright, even NGC 3550 comes in around 14th magnitude photographic. The field also contains a number of other galaxies that have been catalogued in the MCG catalogue. Interestingly NGC 3550 appears to have three cores (or other galaxies superimposed on it). Are these visible? The other galaxy that Herschel found in this area, NGC 3527, which is also thought to be part of the group lies over 45’ away from NGC 3550. The group also makes the Astronomical Leagues Galaxy group and Cluster list. The faintness and tightness of the group means it may also be a suitable challenge for EAA observers. Andrew Robertson using his 24” managed to find 7 members of the cluster.

  You may also need to look this group up as ACO 1185 which is now the preferred prefix for Abell galaxy clusters supplanting the older AGC description which is now used for a different catalogue.

  Owen Brazell - Galaxy Section Director

• NGC 3356 in Leo

  February 2022 - Galaxy of the Month

  NGC 3356 is part of a small group of galaxies in Leo. NGC 3356 itself is classified as an Sb disturbed spiral. It was first discovered by William Herschel in 1784. NGC 3356 is also known as VV 529 from Vorontsov-Velyaminov’s catalogue of interacting galaxies.

  The next galaxy in the field, NGC 3349, was found by Marth in 1865. It is also an interacting system and has the designation VV 514. This object is actually a pair of galaxies, although I think Marth only saw a single galaxy here.

  There is also third galaxy, NGC 3362, close by in the same field, which is another Marth discovery. Marth was using Lassell’s 48” speculum metal telescope from Malta for these discoveries.

  NGC 3356 is obviously distorted and NASA/IPAC Extragalactic Database (NED) suggests that the distorting galaxy maybe UGC 5857. NGC 3356 is thought to be at a distance of around 85 Mpc, although the distance estimates vary quite a lot. Deep images show a lot of star forming regions in its spiral arms and it is very blue.

  NGC 3349 is also a very blue spiral galaxy. It has a companion listed as PGC 2800964 which is probably both a real as well as an apparent companion. PGC 2800964 is heavily distorted and lies at about the same distance as NGC 3349 (approximately 375 million light-years). NGC 3349 is also a radio galaxy. It is also possibly a WR type galaxy which suggests a lot of recent star formation. WR or Wolf-Rayet galaxies show the spectra of Wolf-Rayet stars which suggests the presence of a lot of them, which implies a lot of recent star formation to make these massive stars.

  NGC 3362 is another very blue face on spiral. It is classified as Seyfert 2 and is also a radio source. It has a fairly wide spiral structure delimited by many star forming regions and star clusters. It is not physically associated with the other galaxies, being at quite a different distance.

  Perhaps unsurprisngly none of the galaxies mentioned here make it into the Night Sky Observer's Guide (NSOG) or other observing guides. As Herschel found NGC 3356 it should not be that difficult in medium sized telescopes. Marth’s objects tend to be unspectacular so it is likely that a telescope of 40cm+ will be needed to see NGC 3349 and NGC 3362 on a good night. I would be interested to know what aperture Is required to see the second galaxy in the NGC 3349 pair. The whole group fits in the field of view of a modern hyperwide eyepiece at, say 265x. I suspect that to split the two galaxies in the NGC 3349 pair will require higher power and a dark transparent sky.

  Owen Brazell - Galaxy Section Director

• NGC 3202 in Ursa Major

  January 2022 - Galaxy of the Month

  The small triplet of galaxies in the hind feet of UMa, comprising NGC 3202, NGC 3205 and NGC 3207, were all discovered by William Herschel and must be amongst the faintest of his discoveries. They were all found in February 1788 using the large 20ft which had the 18.7” speculum mirror.

  The group is also included as Holmberg 179, although strictly speaking that is only NGC 3205 and NGC 3207, and WBL 264 which includes just the three galaxies in the trio.

  All of the galaxies in the trio are spirals and NGC 3205 and NGC 3207 show some signs of distortion. The Pan-STARRS image shows NGC 3205 wrapped in shells which suggests a recent merger. It is also suggested that NGC 3205 contains a weak AGN known as a LINER. NGC 3207 it also reported to have an AGN of the same form but is also a low power radio galaxy. It is possible that there is much more activity going on but it is obscured by dust surrounding the nucleus. Perhaps unsurprisingly then NGC 3202 is also thought to contain a weak AGN, also classified as a LINER.

  All three are face on spiral galaxies classified as red and dead, which means there is no star formation going on in them at this time. The group appears to be at a distance of about 330 million light-years from us, which suggests that NGC 3205 at least is quite a large galaxy, comparable in size to the Milky Way. The distances here come from the redshifts so there may be some variation in the actual distances to the group members. Otherwise not much research seems to have been done on the group.

  Perhaps unsurpingly the trio does not make it into the Night Sky Observer's Guide (NSOG) Vol. 2 but is included in Alvin Huey’s booklet on galaxy trios. The group is very tight and will probably require a high power to bring out all the galaxies as they are relatively faint. The group is very compact so will fit in the field of a modern high power wide field eyepiece. It lies only about 41’ from the 4th magnitude star lambda UMa so a high power will be required to keep the glow from this out of the field.

  If you find the main galaxies in the group too easy then try for the edge on spiral UGC 5578, which will also appear in the same medium power field as the rest of the trio. I had half expected the trio to be listed in Wolfgang’s book on Galaxies and How to Observe Them as they appear as a precanned list in Eye and Telescope but they are not there.

  Owen Brazell - Galaxy Section Director