September 11 – Discovery of Messier 2, 1746 (and 1760)

M2, or NGC 7089, is a globular cluster of about 150,000 stars in Aquarius. It was discovered twice: firstly by Jean-Dominique Maraldi on September 11th 1746, and again on the same date 14 years later (1760) by Charles Messier.

Messier 2 (aka NGC 7089)
Messier 2 (aka NGC 7089)

M2 is fairly large, as globular clusters go, at 175 light years across, a little more elliptical in shape than most, and quite elderly (13 billion years old). It is also heading slowly in our direction, at 5.3 km/second. ‘Slowly’, of course, is relative to other intra-galactic speeds. Travelling at three miles a second would be plenty fast enough to get you a speeding ticket down here, but up there it’s nothing special.

(image from
(image from

Theoretically, M2 is a naked eye object if the sky is dark enough, but in practice that doesn’t apply round here in the land of the midnight security lamp. I need at least the small ‘scope to see anything.

Asteroid 125 Liberatrix, discovered by Prosper Henry (or possibly Paul Henry: you can never be sure) on September 11th 1872. It appears to be an M-type, and is possibly the biggest remnant of a larger body.

As for the name, the theory is that it honours Adolphe Thiers, president of the French Republic and suppressor of the Commune, who had recently been instrumental in extracting France from the Franco-Prussian War, in which they were doing none too well.

Asteroid 202 Chryseïs was discovered on this very day in 1879 by C F H Peters. It is about 86 km in diameter, and completes one full rotation every 16 hours as it travels at 17 km/second on its 5.4 year journey around the Sun.

Chryses visit to Agamemnon to ransom his daughter Chryseis (Image: Habib M’henni / Wikimedia Commons)
Chryses visit to Agamemnon to ransom his daughter Chryseis (Image: Habib M’henni / Wikimedia Commons)

In Greek mythology, Chryseïs (also known as Astynome) is indirectly the cause of most of the action in the Iliad. She is captured and enslaved by Agamemnon in Book One, and his refusal to allow her to be ransomed by her father, a priest of Apollo, eventually leads to all sorts of issues.

And while we’re talking of Apollo, asteroid 101955 Bennu was discovered on September 11th 1999 by the LINEAR project. It’s an Apollo, which means it has an orbit that brings it close to Earth, but in the case of Bennu not close enough to hit us (not yet, anyway). This proximity to Earth has led to Bennu being chosen as the target of the Osiris-REX “sample return” mission, which departed planet Earth in September 2016, and will return laden with souvenirs in 2023.

August 16 – Discovery of Asteroid 46 Hestia (1857)

This one is a day overdue. I do a lot of these late at night. Perhaps I shouldn’t.

Main belt asteroid 46 Hestia was discovered on August 16th 1857 from the Radcliffe Observatory, Oxford, by Norman Robert Pogson (1829-1891). Hestia (Greek goddess of the hearth) is a “c type” body of about 124 km diameter. Pogson gave the honour of naming her to astronomer, coin collector, and veteran of the 1810-12 Siege of Cadiz, Admiral William Henry Smyth.

Hestia was one of eight minor planets discovered by Pogson, who also found time to make over fifty thousand observations for a Madras University star catalogue while working in India, discovering 134 stars along the way.

1873 – Discovery of asteroid 133 Cyrene.
1885 – Discovery of asteroid 249 Ilsa.

June 08 – Discovery of Asteroid 146 Lucina (1875)

Prolific asteroid hunter Alphonse Borrelly discovered main belt asteroid 146 Lucina on June 8th, 1875. It was the fifth of his 18 asteroids, and is a dark, carbonacous asteroid, and fairly large, at around 131 to 132 km across.

The name is slightly ambiguous.  Lucina is the name given to the Roman goddess of childbirth, but there are two of them.  While it is usually an epithet given to the goddess Juno, it can also refer to Diana, as both of them were involved in the birthing business.


In 1982, observations of a stellar occultation by Lucina made at the Meudon Observatory in France and reported in the journal Icarus (vol 61, issue 2) recorded a secondary event, possibly caused by a small satellite.  This satellite was estimated to have a diameter of about 5.7 km, and to be about 1600 km from the asteroid.

In 2003, the case for a satellite was strengthened by observations of the orbital motion of Lucina, published in the proceedings of the 34th Annual Lunar and Planetary Science Conference by Jean-Baptiste Kikwaya and others from the Vatican State Observatory.  It’s not absolute proof, but it’s looking likely that 146 Lucina may not be alone.


June 05 – Discovery of Asteroid 248 Lameia (1885)

June 5th, 1885 marks the discovery of asteroid 248 Lameia by Johann Palisa. Lameia is a main belt asteroid of about 50 km diameter, of unknown spectral type. It’s strange that we can know some things about these rocks very precisely, and others not at all. For example, the JPL Small Body Database tells me that the orbital period (year) of 248 Lameia is 1418.617077981085 days. That’s quite precise.

Vain Lamorna, A Study for Lamia – J W Waterhouse (1849–1917)

Lameia takes its name from Greek mythology, as do most early asteroid discoveries. Lamia was a queen of Lybia who made the mistake of becoming one of Zeus’ lovers. The affair panned out in the usual fashion, with Zeus’ wife, Hera, finding out about it, and turning Lamia into a child-eating monster, also seen in some stories to seduce men in order to feed on their blood.

These character flaws may in part be why there is so much about Lamia on the internet.  Or maybe it’s because she got her own character in the Final Fantasy franchise.




May 05 – 70 Panopaea

Asteroid 70 Panopaea was the last to be discovered by our old friend Hermann Goldschmidt at his Paris Observatory on May 5th 1861.  It is a large, dark C-type main belt asteroid about 75 miles in diameter.

Panopaea was a water nymph. She was one of the 50 daughters of Nereus and Doris known as the Nereids (well, I say 50, but if you start counting them up in Homer and Hesiod you end up with about 90). They are particularly associated with the Aegean Sea.

Finding a picture of Panopaea is proving difficult, so here is her father, Nereus.

Herakles and Nereus
Herakles and Nereus

Today’s photograph shows a detail from a Greek black-figure lekythos (oil storage jar) in the Louvre, Paris, decorated by the so-called Istanbul Painter, although this jar was found in Boeotia, southern Greece.  Herakles (Hercules if you prefer) is shown holding onto Nereus in an attempt to extract from him the location of the Apples of the Hesperides.

1853  –  Asteroid 26 Proserpina discovered by Robert Luther, and named after a Roman goddess associated with fertility and agriculture. Proserpina is about 90 km (56.5) km across (possibly a little more) and is an S-type asteroid. It’s a fairly cold place, in common with the rest of the main belt, with a surface temperature of 166 Kelvin (minus 157° Celsius).

May 04 – Launch of “Magellan” on Shuttle Mission STS-30

Happy Star Wars Day.

1886  – on May 4th 1866, asteroid 258 Tyche was discovered by Robert Luther. It is a 650m wide “S” type main belt asteroid, and is possibly a member of the Eunomia family. It was named after the Greek goddess whose Roman equivalent was Fortuna. Her main responsibility was to decide how prosperous a city should be.

1896  –  Asteroid 416 Vaticana was discovered on May 4th, 1896, by Auguste Charlois. It is an S-type main belt asteroid, about 85 km across, and was named after the Vatican Hill (Mons Vaticanvs) in Rome.

1989 – Launch of shuttle mission STS-30 carrying the Magellan probe, aka the Venus Radar Mapper, to be sent on its way to Venus. This was the first ever launch of a spacecraft from a shuttle. Magenta arrived at Venus on August 8th, 1990, and used a high-gain parabolic antenna to allow it to map the Surface through the opaque Venusian atmosphere. The probe burned up in this atmosphere on October 13th, 1994. Being mostly composed of carbon dioxide (96.5%) and nitrogen (3.5%), both of which are colourless, you might think that seeing the surface from orbit would be a doddle, but it is the presence of clouds of sulphuric acid, blowing around the planet at over 200 mph (about 300 km/h) that pose the problem.


The photograph shows the Venusian volcano Sapas Mons, a monster by Earth standards at over 240 miles wide and nearly a mile high.


April 29 – Discovery of Asteroid 68 Leto (1861)

Asteroid 68 Leto was discovered by Robert Luther on April 29th 1861.  It’s a fairly big main belt asteroid (about 125km diameter) with an absolute magnitude of 6.78, and an apparent magnitude from down here of 9.56 when at its brightest.

Leto was the daughter of the Titans Coeus and Phoebe, and mother (by Zeus, as usual) of Apollo and Artemis.  She was thought to have been born on the island of Kos.  Apart from her role in bearing two important gods, Leto is hardly heard about in Greek writing and seems to have been content to remain in the Olympian background.  This fits in with her being generally portrayed as a demure woman, modestly lifting her veil.  The word letho means “to move unseen”, which may explain it.  Perhaps she’s hiding from Hera, Zeus’ wife.

Latona and the Lycian Peasants, by Jan Brueghel the Elder (about 1605).
Latona and the Lycian Peasants, by Jan Brueghel the Elder (about 1605).

The oil painting above, by Jan Brueghel the Elder, shows another incident from Leto’s life, also concerning Hera.  In a foul mood at discovering that Leto was to bear children to Zeus, Hera cursed her to be shunned everywhere she went.  In the painting, she is attempting to drink from a pond in Lycia (southern Turkey), but is being prevented from so doing by the locals, who are stirring up the mud from the bottom of the pond.  She responded by turning them into frogs.

Also today, it now transpires that in 1801 main belt asteroid 69 Hesperia was discovered by Italian astronomer Giovanni Schiaparelli from Milan.  Previously the discovery date had been thought to be April 26, but in an editorial notice of August 29th 2015 the Minor Planet Center announced that an examination of the literature of the time of the discovery shows that the date should in fact be pushed back three days.

Being a patriotic kinda guy, Schiaparelli had named his new discovery in honour of his home country, but for some reason used the Greek name for Italy rather than the Latin (or Italian) one.  The M-type Hesperia is a fairly chunky size, and would be about 130 km in diameter, if it were a sphere (which it isn’t).  I use the word “diameter” a lot in this blog to describe asteroids, but it just means “wide in no particular direction”.

April 28 – Oorter Space

We have two birthdays today.

Johann Oskar Backlund was born on April 28th 1846 in Länghem, Sweden, but after university spent his career in firstly Tartu, Estonia (part of Imperial Russia at the time) and then Pulkovi (also Russia). He was a dab hand at celestial mechanics, and became so well known in Russian astronomical circles for his work on comet 2P/Encke that Russian sources sometimes refer to it as Encke-Backlund.

Oskar Backlund
Oskar Backlund


2P/Encke is believed to be the source of the Taurid meteor shower, but Backlund was more interested in the effect it might be having on Mercury, and used the perturbations produced by the motion of the comet to predict the mass of the planet. If I had a copy of the 1961 journal Soviet Physics I might be able to share his results with you (unless they were in Russian, which seems likely).

Jan Oort was also born on this day, in 1900, in Franaker, Friesland (the Netherlands). He was mostly drawn to radio astronomy, and his day job was as a professor at the University of Lieden, under Director Ejnar Hertzsprung. Among Oort’s many career highlights were the discovery of a group of stars outside the Milky Way (the galactic halo), the calculation of how far away and in what direction lies the centre of the galaxy, and of course the idea that comets originate in what is now commonly known as the Oort Cloud, a roughly spherical region of icy planetesimals surrounding the Sun at distances of up to an almost unbelievable 50,000 AU (defining the limits of our home star’s gravitational supremacy).

Jan Oort (image: Nationaal Archief NL Fotocollectie Anefo)
Jan Oort (image: Nationaal Archief NL Fotocollectie Anefo)

1903  –  Discovery of asteroid 509 Iolanda (a.k.a. 190LR) by Max Wolf. Iolanda is an S-type main belt asteroid, and the NASA JPL Small-Body Database Browser gives it a diameter of just under 53km, an absolute magnitude of 8.40, and a rotation period (day) of 12.306 hours.

1928  –  Birth of Eugene Shoemaker, a leading light in the development of astrogeology, but mostly remembered these days as co-discoverer of comet Shoemaker-Levy 9, which famously collided with Jupiter in 1994.

1999  –  Launch of the ABRIXAS X-Ray Telescope by the German Deutsches Zentrum für Luft und Raumfahrt from the Kapustin Yar facility in Russia. The mission lasted approximately three days, thanks to an accident involving an overcharged battery.

2003  –  Galaxy Evolution Explorer (GALEX) launched.

April 26 – Discovery of Asteroid 83 Beatrix (1859)

1859  –  Birth of Italian astronomer Vincenzo Cerulli, one of the first people to suggest that Martian canals might be an optical illusion.  Cerulli discovered one asteroid, 704 Interamnia, named in honour of his home town.  Wikipedia has his birthday as April 20th, but other sources seem to agree on the 26th.

1865  –  Asteroid 83 Beatrix discovered by Annibale de Gasparis, another Italian.  It is an X-type asteroid, signifying it is part of a group of bodies with similar spectral characteristics, but not necesarily similar compositions.  This one was named for Beatrice Portinari, popularly thought to be the inspiration for the guide Beatrice in Dante’s Divine Comedy.

"Dante and Beatrice" b y Henry Holiday. (Beatrice is second from the left.)
“Dante and Beatrice” b y Henry Holiday. (Beatrice is second from the left.)

1876  –  Asteroid 163 Erigone discovered by Henri Joseph Anastase Perrotin, director of the Nice Observatory, and discoverer of six asteroids.  A rare opportunity was missed last year when Erigone occulted the first magnitude star Regulus.  This kind of happening is rarely seen from heavily populated areas, and this one would have been visible from a small track that included New York.  Unfortunately Spode’s Law came into effect and it rained heavily throughout the quarter of an hour of the event.

1884  –  Main belt asteroid 236 Honoria discovered.  Honoria is named after the sister of Emperor Valentinian III.  She gets into the history books mostly as the perpetrator of one of the worst decisions ever made: asking Attila the Hun to help her get out of a dull marriage.  Honoria was discovered by Johann Palisa.  it is about 86 km across, and is a stony S-type.

1933  –  Birth of Arno Penzias, co-discoverer with Robert Wilson of the cosmic microwave background radiation, the faint echos of the Big Bang.

1957  –  Transmission of the first episode of “The Sky At Night” by the BBC.  Under the legendary Sir Patrick Moore, it became the longest running television programme in the World to have one presenter. It’s not quite the same these days, but new presenter Maggie Aderin-Pocock (she will always be the “new” presenter to some of us) is growing on me.

1962  –  Launch of Ariel 1 (UK 1) the first British satellite.  Surprisingly, given our lackluster approach to spaceflight today, this launch made the United Kingdom the third country on the planet to have their own satellite (but we needed the Americans to launch it for us from Cape Canaveral).

April 25 – Birth of Astronomer Gérard de Vaucouleurs (1918)

Born today in 1918, Gérard de Vaucouleurs was a French astronomer who specialized in galaxies.   He is best known these days for his modification of Edwin Hubble‘s galaxy classification scheme.  De Vaucouleurs added barsrings and spiral arms to Hubble’s basic system of ellipticalspiral and lenticular galaxies.

Barred Spiral Galaxy NGC 1300 (image credit: NASA/ESA).
Barred Spiral Galaxy NGC 1300 (image credit: STScI/NASA/ESA).

In honour of Monsieur de Vaucouleurs, Today’s photo (a composite image by the Hubble Space Telescope) shows the most barred, armed, spiral galaxy I could find.  NGC 1300 is in the constellation Eridanus. It was discovered by John Herschel in 1835, and is a member of the Eridanus Cluster of about 200 galaxies.

 1848  –  The large main belt asteroid 9 Metis was discovered by Irish astronomer Andrew Graham.  It was to be the last Irish asteroid for 106 years.

1890  –  Asteroid 291 Alice, of the Flora family, discovered by Johann Palisa. Alice is roughly the shape of a giant jelly bean, at about 19 x 12 x 11 km.

1890  –  Asteroid 292 Ludovica was also discovered today, and was also one of Johann Palisa’s. Palisa was obviously smoking on April 25th, whereas Auguste Charlois was probably steaming some time afterwards, as he too discovered both asteroids, but on the 26th.

1906  –  Asteroid 599 Luisa was discovered from Taunton, Mass., by prolific American asteroid and comet hunter Joel Hastings Metcalf. The origin of the name isn’t known, but I would like to point out that Metcalf’s father was called Lewis.

1993  –  Launch of X-ray telescope Alexis (Array of Low Energy X-Ray Imaging Sensors).