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.
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.
1892 – Asteroid 326 Tamara, discovered March 19 1892 by Johann Palisa. It is a C-type asteroid of about 93 km wide in the main belt, named after Tamar the Great, Queen of Georgia.
1892 – Asteroid 332 Siri was also discovered on March 19th 1892, but by Max Wolf at Heidelberg. It’s a fairly small object, about 40km wide. The origin of the name is not known, and I haven’t been able to find any likely candidates. Part of the problem, of course, is that, as with the aforementioned Tamara, and the next on this page, Isara, the name could have been altered to fit some perceived idea of what an asteroid’s name should sound like.
1893 – Asteroid 364 Isara was discovered by Auguste Charlois. It is a member of the large Flora family of S-type asteroids, which may be parents of the L chondrite meteorites. The Isère river, from which this asteroid derives its name, flows from the Alps and joins the Rhone near Valence in southern France.
1919 – Karl Wilhelm Reinmuth discovers asteroid 911 Agamemnon, a “Greek camp” Jupiter Trojan of approximately 83 km radius (making it probably the second biggest).
Asteroid 136 Austria was discovered on March 18th 1874 by Austrian astronomer Johann Palisa. Because it was his first discovery, he got a bit patriotic when it came to choosing a name, although he did stick to the convention of Latinising the name, rather than use Österreich or Oesterreich.
136 Austria is in the main belt, is about 40 km wide, and may or may not be an M-type. A study by Clarke et al published in the Abstracts of the 25th Lunar and Planetary Science Conference suggest it may be more of an S-type.
1853 – Asteroid 78 Diana was discovered on March 15th, 1853 by Robert Luther, the German astronomer who discovered 24 asteroids. According to IRAS observations Diana is about 120 km across, a figure that matches quite well with the 116 km diameter obtained from observations of the occultation of star SAO 75392 in 1980.
Diana is named after the Roman goddess of the hunt, and her Greek equivalent, Artemis, will be turning up in these pages later in the year (discovered September 16th, 1868).
1873– Asteroid 118 Peitho discovered by Robert Luther. This main belt asteroid is about 47 km in diameter, and categorised as S-type. There are a couple of Peitho‘s in Greek mythology, with the most likely candidate for this naming ceremony being the goddess of seduction, an attendant of Aphrodite. Her Roman name, Suada, presumably shares a root with the Latin persuadere , the place from where we get the middle English word persuasion.
Captain Alan LaVern Bean, USN, was born on this day in 1932 in Wheeler, Texas (100 miles east of Amarillo).
Bean clocked up 69 days in space aboard Apollo 12 (he was the 4th person to undertake the highly improbable act of walking on the Moon) and Skylab mission SL-3. Following his retirement from NASA, Bean turned his attention to painting. As far as I know, he is the only artist to incorporate genuine Moon dust into his work.
1895 – Asteroid 400 Ducrosa discovered by Auguste Charlois. It was named after Joseph Ducros, a technician at the Nice Observatory.
Captain Eugene Andrew Cernan USN, born this day in 1934 in Chicago, Illinois. A veteran of Gemini 9A and Apollo 10, Cernan was also last man back to the lunar module Challenger on the Apollo 17 mission, and therefore currently holds the honour of being the “last man on the Moon” (which is also the title of his memoir). He is also a member of one of the most exclusive clubs ever– the extremely small collection (three) of people who have been to the Moon twice. And as if that weren’t enough, he holds the lunar land speed record (11.2 mph).
Gene Cernan died in Houston, Texas, on January 16th, 2017.
1879 – Birth of Albert Einstein in Württemburg. Where do you start? Probably by saying “Google him”. Einstein’s main claims to fame are, of course, Special Relativity (1905), a theory describing the relationship between space and time, and General Relativity (1915), which concerns gravitation. He also, in 1916, predicted gravitational waves, almost exactly 100 years before they were discovered
1885 – Asteroid 247 Eukrate discovered by Robert Luther..
1904 – Asteroid 524 Fidelio discovered by Max Wolf.
Uranus(named after a primal Greek god of the sky, the son and husband of Gaia, and father of the Titans) was discovered on this day in 1781 by William Herschel. It’s the 7th furthest planet from the Sun, orbiting at approximately 2.8 billion km, and is often classed as an ice giant with Neptune, as well as being a gas giant. Uranus is the third largest planet by radius (about 25,000km, or 4 Earths), but only the fourth largest by mass (roughly 14 times as massive as Earth).
As with the other giant planets, Uranus has a plentiful supply of moons (27 at the last count). The largest five are Oberon, Titania, Umbriel, Miranda and Ariel. None of the Uranian moons are particularly large, with the biggest, Titania, being less than half the size of our Moon. The naming convention for Uranian moons is that they are all characters from either the plays of Shakespeare or The Rape of the Lock by Alexander Pope. Most of the Shakespearean names were taken from The Tempest and A Midsummer Night’s Dream, but I suppose they started running out after a while, so nowadays anything goes.
Uranus also has a ring system. The rings, of which 13 are known, are dark, narrow, and probably quite young (less than 600 million years old). They are thought to be the remnants of one or more shattered moons. The rings can be clustered together in three groups: nine main rings, two dusty ones, and two outer rings, including the brightest, the ε (epsilon) ring.
The atmosphere of Uranus (by which I mean the outer layers) usually presents a blank face to watching humans, and the Voyager photographs painted a picture of a serene world. But recently (August 2014) a collection of enormous bright spots have been observed, showing that giant storms can sometimes flare up on the planet.
1980 – CALYPSO, one of the smaller of Saturn’s fifty-three named moons, was discovered on this day in 1980. It’s an irregularly-shaped Trojan, trailing 60 degrees behind the larger moon Tethys at the L5 Lagrangian point, something I’m still planning on writing a blog about (another Trojan, Telesto, occupies a position 60 degrees ahead of Tethys, called the L4). Calypso is named after a daughter of the Titans Oceanus and Tethys.
1969 – APOLLO 9, under the command of James McDivitt, splashed down in the North Atlantic on March 13th 1969, after just over 10 days in orbit.
1855 – Birth of Percival Lowell, proponent of Martian canals, and founder of the Lowell Observatory, one of the oldest in the United States.
Today, in 1787 in Bavaria, Joseph von Fraunhofer, inventor of the spectroscope, and discoverer of the Sun’s absorption lines, was born.
Unfortunately for the worlds of optics and astronomy, Fraunhofer died on June 7th, 1826, at the young age of 39 (early death was an occupational hazard for glassmakers in those days due to the poisonous heavy metal vapours associated with the craft).
Fraunhofer lines are dips in the intensity of starlight that are now known to coincide with absorption of energy by certain elements in the atmosphere of a star. On a visible spectrum, the lack of energy shows up as dark lines.