May 31 – Discovery of asteroid 892 Seeligeria

A lesson in how to crowbar a name into an asteroid, 892 Seeligeria was discovered on May 31st, 1918, by Max Wolf, and named after German astronomer Hugo Hans Ritter von Seeliger.

Hugo von Seeliger.

Seeligeria is in the main asteroid belt, is approximately 38 km (23.6 miles) in diameter and has a year lasting almost 6 Earth years.  On average it is about 3.2 AU from the Sun, although it’s elliptical orbit means it can be as close as 2.9 AU, and as far away as 3.5 AU.

Seeligeria is a member of the Alauda family of more than 1,200 known carbonaceous asteroids, containing a variety of interesting names, including  3325 TARDIS, which hardly needs an introduction, likewise the great violonist 52344 Yehudimenuhin and the alma mater of Anton Checkov and Mikhail Gorbachev, 6355 Univermoscow.

Von Seeliger (1849 – 1924), was a prominent astronomer in his day, and also professor of astronomy at the University of Munich, where one of his PhD students was Karl Schwartzschild, who gave us the Schwartzschild radius (I’m not going to try to define this here, so I have included a rare thing in these blogs: a hyperlink).


1918: Asteroid 893 Leopoldina.  It was not unusual for the likes of Max Wolf to discover two asteroids in a day, and today is one of those days.  893 Leopoldina is another main belt asteroid, also 38 km in diameter, but not a member of the Alauda family.  Leopoldina is named in honour of the Academy of Sciences Leopoldina, in Halle, Germany.

1975: The European Space Agency is formed.

2008: Launch of space shuttle mission STS-124 to the International Space Station.  The crew of seven took with them a substantial part of the Japanese Experiment Module (the biggest single ISS module), a Buzz Lightyear figure, and spare parts for a malfunctioning toilet.  Spaceflight isn’t all glamour.


May 30 – Messier 12

Today’s main event is not dissimilar to yesterday’s. It happened in 1764, and was the discovery of a globular cluster, Messier 12, (or NGC 6218), by Charles Messier, one day after he discovered globular cluster M10. And at a casual glance, the photograph I’m using today looks remarkably similar to the one I used yesterday. But I’ve had a close look, and they definitely two different balls of stars.

Messier 12 from the Hubble Space Telescope (image credit: NASA / STScl / ESA)
Messier 12 from the Hubble Space Telescope (image credit: NASA / STScl / ESA)

M12 is approximately 75 light years across, at a distance from Earth of about 15,700 light years. It can be located as a faint fuzz in the constellation Ophiuchus with good binoculars, but needs a fairly hefty telescope to bring out detail.

Location of M12 (image created using Stellarium)

I suppose the obvious question, with M10 on the 29th of May and M12 on the 30th is: what about Messier 11? Unfortunately for Charles M11 had already been discovered. He included it in his catalogue, but German astronomer Gottfired Kirch beat him to it by a mere 63 years. M11 is in the constellation of Scutum (the shield), and is commonly known as the “Wild Duck Cluster”.

Extrasolar planet MOA-2007-BLG-192Lb (or just MOA-192b to its friends) was discovered orbiting the low mass red dwarf of the same name (but without the “b”) on May 30, 2008. Spotted by the MOA-II gravitational microlensing survey, it is one of the smaller known extrasolar planets (about 3 times the mass of Earth) and has an appropriately tiny parent star of about 6% the size of the Sun.

1903 – Asteroid 511 Davida discovered in 1903 by R S Dugan and named after astronomer David Peck Todd.

2007 – Saturn’s tiny moon Anthe was first spotted in Cassini images. Anthe may be part of a dynamical family with the moons Methone and Pallene. This is appropriate if true, as they were sisters in mythology, three of the Alkyonides, who threw themselves into the sea when their father was killed by Herakles.

1963 – Happy birthday Helen Sharman, OBE, Sheffield native, chocolate chemist and first Briton in space. She flew on Soyuz flight TM-12 to the Mir space station. It was her only mission.

May 29 – Discovery of M10, 1764

The globular cluster Messier 10, discovered by Charles Messier, unsurprisingly, was described by him as a “nebulous patch without stars” on May 29th, 1764, after which he could relax and ignore it, safe in the knowledge that it was not a comet, and therefore unworthy of further attention.  M10, also known as NCG 6254, is in the large, equatorial constellation of Ophiuchus, “the serpent bearer”, and is about 80 light years across, meaning it should occupy an area of the sky two-thirds that of the full Moon.  This sounds impressive, but if you find it in the average telescope it won’t look anything like that big, because you will only be able to see the core.

Messier 10 (Image credit: NASA / STScI / ESA)

This beautiful photograph was taken by the Hubble Space Telescope, and shows the core of M10, at a distance of about 15,000 light years.

Yet another asteroid day.  Today we have 72 Feronia, discovered on May 29 1861 by the German-American astronomer Christian Heinrich Friedrich Peters, who went on to find another 47, so he must deserve a birthday shout-out on September 19.

Feronia is a large, dark main belt asteroid, about which there isn’t much to say except that it has a diameter of about 86km, a rotation period of a little more than 8 hours, and takes over 3 years to orbit the Sun.

Feronia’s namesake is a Roman goddess, variously associated with fertility, health and wildlife. She was apparently very popular among plebeians, and as I’m one myself I must remember to tweet her feast day on November 13.

Marble head, suspected to be that of Feronia (Museo Civico Rieti, Italy).

1889  –  Discovery of asteroid 284 Amalia  by Auguste Charlois.

Updated: May 2019.

May 28 – Discovery of Asteroid 99 Dike

Asteroid 99 Dike was the first of many asteroids (and the occasional comet) to be discovered by Alphonse Borrelly (1842-1926) from his Marseilles observatory. This one was spotted on May 28th 1868.  I have very little to say about it, except that I think it should be pronounced die-kee rather than dyke or decay.

99 Dike has been shown, like three-quarters of all known asteroids, to be a carbonaceous “C-type”, meaning it has a high carbon content, which also means it is dark in colour.  According to the JPL Small Body Database, Dike is about 67km across, takes 1,589 days to orbit the Sun, and has an absolute magnitude of 9.43.

Dike Astrea was a daughter of Zeus and Themis, and was the goddess in charge of justice and fair judgement in the mortal world (her mother had the same responsibility over the immortals).

Dike Astrea (credit : GearedBull at Wikipedia)

May 27 – Discovery of Asteroid 44 Nysa

Asteroid 44 Nysa is head of the Nysian family of main belt asteroids.  It is a type E asteroid, a group thought to have surfaces of the orthorhombic silicate enstatite, a name I remember well from my days spent hopelessly trying to remember mineral compositions for Mr Hughes’ A-Level Geology class.

Nysa was discovered on May 27th 1857 by our old friend Hermann Goldschmidt, and named not after a person or mythical creature, but a place.  Nysa was a mythological land, linked to Africa , Arabia, or more likely India, where Dionysus was raised by the Hyades.

Image of Dionysus, Nysa’s most famous son. (Image credit: unknown source.)

Because of the rarity of E types, Nysa has been the subject of some scrutiny, and has attracted that attention of both the most famous space-borne telescope (Hubble) and what was until 2016 the biggest ground-based one (the 1,000 foot Arecibo dish in Puerto Rico).  There are suggestions that Nysa might not be a single bosy, but a “contact binary”.


1887  —  Discovery of asteroid 267 Tirza by Auguste Charlois (the first of his 99 asteroid discoveries).

Created: May 2019.

May 26 – Launch of EXOSAT

The European X-Ray Satellite (EXOSAT) was launched on May 26th 1983, and was operational until April 9th 1986, studying x-ray binaries, active galactic nuclei, and other x-ray sources. Personally I think the best thing about it was its bizarre orbit (from 120,000 mile apogee to 300 mile perigee), but there were other highlights of the three years, including the discovery of quasi periodic oscillations in LMXRBs and x-ray pulsars. I can sense that you are just dying to know what LMXRB stands for. It’s Low Mass X Ray Binary (low mass is a little misleading, generally meaning lower in mass than the Sun).

1969Apollo 10 splashdown. Tom Stafford, John Young and Eugene Cernan were recovered by the USS Princeton, about 400 miles from American Samoa, in the Pacific Ocean. Their 8-day mission had included four orbits of the Moon, as a rehearsal for “the big one”, which was to take place later the same year.

Recovery of the Apollo 10 capsule
Recovery of the Apollo 10 capsule

1826 – Birth, in Chelsea, of Richard Christopher Carrington, recipient of the Gold Medal of the Royal Astronomical Society. His work included the demonstration of the existence of solar flares, and their influence on our planet. He now lends his name to the numbering system for sunspot cycles.

Last updated: May 10, 2019.

May 25 – Launch of Skylab 2 (SL-2)

Skylab 2, launched today in 1973, was the first manned mission to NASA’s orbiting Skylab space station, prior to setting a new record of 28 days for the longest time spent in space (back in those days it was a lot more about setting records to get one over on the Russians than it is now). The actual Skylab station had already been launched, unmanned, on May 14th, in what was to be the final mission of the gigantic Saturn V rocket.

The Skylab Orbiting Space Station (image credit: NASA).

The crew comprised three astronauts; a famous veteran and two rookies. Flight commander, Charles “Pete” Conrad, third man on the Moon, was on his fourth mission, pilot Paul Weitz was making the first of his two (the other would be on the maiden voyage of the shuttle Challenger), and Joseph Kerwin was on his only venture beyond the atmosphere (which made him the first physician in space).

The crew of SL-2 (image credit: NASA).Fb

Following their launch atop a Saturn 1B, at 13:00 UTC, the crew took less than a day to reach Skylab, after which they set about trying to minimise the impact of the damage the staion had sustained at launch. It was missing its micrometeorite shield and part of the solar power array. Also, the remaining solar panel was jammed by a strap, possibly from the meteorite shield.

A partially deployed solar array, and the errant strap preventing it from unfurling (image credit: NASA)

Fortunately, it was known there would be a few issues before the crew lifted-off, so launch was delayed by ten days to allow for training on how to conduct repairs in orbit. It took some doing (they almost reached double figures in docking attempts, and had to use a foldable parasol to protect parts of the already blistered station from overheating) but eventually Skylab was brought up to a level that would allow future mission to be less stressful.

Skylab 2 Mission Patch. Spot the not-so-deliberate mistake? (Image credit: NASA)

May 24 – Launch of MA-7

Mercury Atlas 7, combining Mercury craft 18 and Atlas launch vehicle 107-D, was launched on May 24, 1962, with the capsule bearing the slightly more memorable name of Aurora 7. It was a fairly short flight for pilot M Scott Carpenter, the fourth American in space, lasting a little under 5 hours. But that was still time for him to circle the Earth three times, photographing his home planet and studying the behaviour of liquids in weightlessness, before coming down approximately 250 miles off course.

Mercury Atlas 7 (image credit: NASA)
Mercury Atlas 7 (image credit: NASA)

Asteroid 131 Vala was discovered on May 24th, 1873, by Christian Heinrich Friedrich Peters, and named after a Norse prophetess. It is a K type, main belt asteroid of approximately 35 to 40 km diameter.
Vala is the anglicisation of the old Norse word völva, meaning “wand carrier”, and refers not to a specific individual, but to a class of seeress, feared and revered by society, and in the habit of carrying a wand.

May 22 – Discovery of Asteroid 41 Daphne

Asteroid 41 Daphne was discovered on May 22nd 1856 by Hermann Goldschmidt. It is a C-type (i.e. dark and mostly carbon), main belt asteroid, orbiting in 9:22 mean orbital resonance with Mars, meaning that every 9 times Daphne orbits the Sun (about 15,113 days) Mars goes round almost exactly 22 times, which is the same distance.

Daphne was a nymph who attracted the attention of the god Apollo. She wasn’t keen on his advances, though, and pleaded for help to her father, a river god. His bizarre solution to her problem was to turn his daughter into a laurel tree.

Apollo and Daphne, by Veronese.
Apollo and Daphne, by Veronese.

Asteroid 41 Daphne has a satellite, S/2008 (41) 1, named Peneius, after the river god mentioned above, discovered on March 28, 2008. Peneius orbits Daphne every 1.1 days.

Thomas Gold was born on this day in 1920. Gold was an Austrian-born astrophysicist, proponent of the steady state theory of the universe, whose family fled to Britain when the Germans invaded (his father was a wealthy Jewish industrialist) . The British government, compassionate and understanding as always, had him thrown into an internment camp as an enemy alien for the first two years of the war, but later relented and put him to work on radar development.

1900 – Asteroid 455 Bruchsalia was discovered by Max Wolf. It sounds like it might be an Italian sandwich, but this main belt asteroid is actually named after the German city of Bruschal.

Last updated May 09, 2019.

May 19 – Discovery of Asteroid 14 Irene

Asteroid 14 Irene, was discovered on this day in 1851 by the Nottingham-born astronomer John Russell Hind (1823 – 1895).

Being the size she is (about 150km in any direction) and having such an early discovery date and low classification number, I’m amazed it’s taken me five years to get around to her.

Irene is an “S” type asteroid, meaning her composition is of a siliceous nature. S-types are generally brighter than the much more common “C-type” carbonaceous asteroids, presumably making them easier to spot back in the early days of asteroid hunting.

Roman Statue of Eirene with the infant Plutos (God of Wealth).

In mythology, Irene, or Eirene, was one of a collection of deities called the Horae. The root of this name is from the word “year”, and the Horae were originally in charge of the seasons.  Later though, more of them were employed to look after some of the more nebulous aspects of the natural order of things, such as peace (out friend Eirene here), plant growth (Auxo), moral justice (Diké) and law (Eunomia).


1874 —  Discovery of asteroid 138 Tolosa by Henri Joseph Perrotin. Tolosa is the Latin version of Toulouse.

1881  —  Discovery of asteroid 220 Stephania (Princess Stephanie of Belgium) by Johann Palisa.

1893  —  Discovery of asteroids 367 Amicitia (friendship) and 368 Haidea (unknown name), both by Auguste Charlois.

Created May 2019.