March 20 – Discovery of Messier 96 (1781)

The third of today’s three Messier objects is Messier 96. It was identified by Messier’s assistant Pierre Méchain, and is the largest member of the Leo 1 group (also known as the M96 Group). Unlike M95 (see last post) it has an asymmetrical structure and an off-centre nucleus, the result of gravitational interractions with other members of the group.


M96 is not easy to find. The photograph here was taken by the 8.2 metre Very Large Telescope (great name) at the European Southern Obsrvatory in Chile. You shouldn’t expect to see anything like this through your binoculars, because you will be disappointed.

March 20 – Discovery of Messier 93, 1781

Messier 93, NGC2447, was discovered on this day in 1781. This binocular object is an open cluster about 3,600 light years away, spanning approximately 10 light years, in the constellation Puppis. It was the last open cluster to be discovered by Charles Messier himself. M93 contains a good collection of blue giant stars, as well as quite a few red giants, possibly in clusters of their own. It’s hard to say how many stars a cluster contains, mainly because they get in each other’s way when you try to count them. This one has at least 80 identifiable members, but may well turn out to be several hundred strong.


March 04 – Discovery of Messier 85 (1781)

1781  –  Messier 85, a lenticular (elliptical if you prefer) galaxy, was discovered on this day in 1781 by Pierre Méchain.  It can be found in the constellation Coma Berenices (named after the Egyptian queen Berenice II) and is about 60 million light years away, making it the northernmost galaxy in the Virgo Cluster, a collection of somewhere between 1,200 and 2,000 galaxies, on the periphery of which is our own local group.

M85 (image credit: NOAO / AURA / NSF)
M85 (image credit: NOAO / AURA / NSF)

There are hundreds of beautiful photographs of all manner of galaxies on the internet, but M85 is very under-represented by legal entities with relaxed media sharing policies, hence the above.

1861  –  Asteroid 64 Angelina discovered from Marseilles by Ernst Tempel.  Angelina is an E-type (containing enstatite) with a very high albedo (0.28) compared to many other asteroids.  It is named after an astronomical station operated by the Hungarian astronomer Franz Xaver von Zach.  For discovering Angelina (and 65 Cybele) Tempel received the ‘Lalande Prize’ from the French Académie des sciences.

1892  –  M-type (mainly metallic) main belt asteroid 325 Heidelberga was discovered today by Max Wolf.  If you’ve been following these pages closely the choice of name should come as no surprise, being the location of most, if not all, of Wolf’s discoveries. Heidelberga is reasonably large, at approximately 75 km in diameter.  Fuller details of Heidelberga’s physical and orbital characteristics can be found in the NASA JPL Small-Body Database browser.

1904  –  Birth of George Gamow, cosmologist, and early champion of the Big Bang theory.

1923  –  Birthday of Patrick Moore, amateur astronomer extraordinaire.

This post originally appeared in 2015, and was slightly updated in 2017.


August 10 – Discovery of M110 (1773)

They say that the date on the earliest known drawing of this . . .

Messier 110 (image: D. Geisler/NASA/ESA/STScI)

. . . says August 10th, 1773, so we have to assume that Charles Messier did indeed discover the dwarf elliptical galaxy M110 on that date.

It was also, though, discovered independently by prolific comet hunter Caroline Herschel, ten years later, and there seems to have been a reluctance to add it to the Messier catalogue, as it has only been in there since 1967 (it is the last of the 110 items on the list).

M110 has a massive neighbour. It sits alongside the Andromeda Galaxy (M31), which may account for Messier not listing it, and it isn’t even M31’s only satellite. Andromeda has a family of more than a dozen dwarf galaxies, including M32, on the opposite side, which is brighter than M110, despite being only half the size, so it might not be so strange that M110 took so long to enter the Premier League (sorry Charles – “Ligue Un“) of deep sky objects.

M110 is located about 2.6 x 106 light years away from us, and is also known as NGC 205. It measures approximately 8,500 light years across, and may be as massive as 15 X 109 solar masses, though opinions vary on this subject. Unusually for a dwarf galaxy, it contains dust clouds, evidence of “recent” star formation.

If anyone can tell me why people online are calling M110 the “Edward Young Star”, I’d be grateful, because that name isn’t in any of my astronomy books.

March 24 – Concordia

On March 24 1860 Karl Theodor Robert Luther discovered the C-type asteroid 58 Concordia from the Düsseldorf-Bilk Observatory.  As you may remember (I mention it every so often) Luther discovered 24 asteroids in all.  This one was named after the Roman goddess of marital harmony and understanding.  The name was chosen by Karl Christian Bruhns, the recently appointed professor of astronomy at the University of Leipzig.

Concordia (image credit: Andreas Praefcke)
Concordia (image credit: Andreas Praefcke)

Concordia is a main belt asteroid, 90-odd km wide, orbiting at between 2.5 and 2.8 AU, and taking 4.44 years to orbit the Sun.  It is a member of the Nemsis family, a medium-sized asteroid family with about 250 known members, predominantly C-types.

1781   –   Messier 105 (NGC 3379).  If you think back a couple of days you might remember me mentioning a group of galaxies in Leo containing M95 and M96, both of which were discovered on March 20th 1781.  M105 is also in the group, and it was discovered on March 24th 1781, also by Messier’s assistant Pierre Méchain, who was on a roll.  Unlike the other two, this one is an elliptical galaxy, and is known to have a supermassive black hole at its centre.

M105 (image credit: NASA)
M105 (image credit: NASA)

M105 is the brightest elliptical galaxy in this particular group.  It is an E1 type, and is approximately 38 million light years away from Earth.  The “E” rating for galaxies is based on their elongation, where “E0” is fairly round, while “E7” is extremely stretchy.  E1 galaxies are only slightly elongated.

March 22 – Messier 94

Messier 94, also known as NGC4736, was discovered today in 1781 by Pierre Méchain. It is a spiral galaxy in the constellation Canes Venatici, and is about 16 million light years (4.91 megaparsecs) away from us.

M94 (Image: NASA; JPL; Spitzer)
M94 (Image: NASA; JPL; Spitzer)

M94 has its own grouping of galaxies within the Virgo Supercluster, called (unsurprisingly) the M94 group . The group has about 20 members.

Asteroid 327 Columbia was discovered by Auguste Charlois on March 22nd, 1892. It is in the main belt, has an absolute magnitude of 10.1, and is of unknown spectral type.

Asteroid 327 was named after Christopher Columbus, the Genes explorer who helped kick-start the Spanish colonisation of the Americas.  Any mental image you might have of Columbus’ appearance is from a portrait made after his death.  There are no known paintings of Columbus dating from his lifetime.  So I won’t be including one here.