Star Constellation Facts: Leo Minor

Star Constellation Facts: Leo Minor

While the Greek astronomers Ptolemy and Aratus considered the region now occupied by Leo Minor to be empty, or at least, not organized into a recognizable pattern, the Polish astronomer Johannes Hevelius thought otherwise. Therefore, to bring order where chaos reigned, in 1687 he co-opted 18 of the stars between Ursa Major to the north, Cancer to the southwest, Lynx to the west, and Leo to the south into a pattern he called Leo Minor (“Smaller Lion”). The constellation ranks at 64th in terms of size, taking up an area of just 232 square degrees of the night sky between latitudes +90° and -40°


Leo Minor is a diminutive and faint northern sky constellation that requires exceptionally good eyesight and seeing conditions to be seen at all, and even then an observer is likely to only see its three brightest stars that form a triangle. In the northern hemisphere, Leo Minor can be seen during the winter and spring time, with the constellation reaching its highest point above the horizon at midnight (Local Time) on February 24th, and again three months later, at 9 PM (Local Time) on May 24th. On star charts, the constellation’s shape outline resembles a stingray with its “tail” extending toward the constellation Lynx. Look for Leo Minor between the constellations Leo to the south, Cancer to the southeast, Ursa Major to the north, and Lynx to the west.

Notable Stars

– Praecipua (46 Leonis Minoris) is a 3.83 visual magnitude, K0+III-IV-class orange sub giant star located about 95 light years away. The Latin name, Praecipua, translates into “the chief [star of Leo Minor]”. The star is 8.5 times as big as the Sun, 32 times as bright, and 1.5 times as massive.

– Beta Leonis Minoris is a binary star, and the second most luminous star in the constellation. The two components are classified as G8III-IV and F8IV respectively, meaning that the first is a yellow subgiant, and the second a yellow white subgiant. The brighter of the two stars has an apparent visual magnitude of 4.40, and is about 36 times as bright, 7.8 times as big, and about twice as massive as the Sun. The other star in the system has an apparent visual magnitude of 6.12, and is about 5.8 times as bright, twice as big, and about 1.35 times as massive as the Sun. The system is located about 146 light years away.

Star Constellation Facts: Leo Minor– RY Leonis Minoris (G 117-B15A) is a pulsating white dwarf with an apparent visual magnitude of 15.5. There are many similar white dwarfs in the sky, but this particular 400-million-year-old example’s pulsation period of 215 seconds is so stable that it loses only about one second in every 8.9 million years, making it the most stable celestial time keeper ever discovered.

Notable Objects

The constellation may not have famous Messier objects, but it does have one of the strangest celestial objects to be found anywhere, namely:

-Hanny’s Voorwerp (Hanny’s Object); this “quasar ionization echo” is an exceedingly rare type of object that at the time of its discovery by Dutch amateur astronomer Hanny van Arkel in 2007 was considered by professional astronomers to be an “unidentified” object. Hanny’s Voorwerp is located close to the spiral galaxy IC 2497, and appears to be part of a gaseous streamer that partially surrounds the galaxy. It is only visible because a light source within IC 2497, believed to be a black hole, is illuminating a part of the streamer; much like a streetlight illuminates only a part of a dark street surface. The object is about the size of the Milky Way Galaxy, with a big central hole that spans about 16,000 light years.

There is evidence of large numbers of stars being formed in the part of Hanny’s Object that faces the illuminating galaxy, probably as a result of a huge outflow of gas from the galaxy that is colliding with gas and dust in the object. It is worth noting that the youngest of the newly formed stars are all several million years old. The object and IC 2497 are both about 650 million light years away.

– NGC 3432, also known as the Knitting Needle Galaxy, is located only about 3 degrees to the southeastward of the star 38 Leonis Minoris. With an apparent visual magnitude of 11.67 and at a distance of 42 million light years, this edge-on galaxy is an easy target for most amateur telescopes.


Two stars in the constellation, HD 87883 and HD 87883, each hosts one planet, although in the case of HD 82886, it is suspected that several planets smaller than the confirmed 1.3 Jupiter-mass planet may be orbiting the star.

Meteor Showers

This minor shower with an uncertain maximum rate peaks between October 18th and October 29th, and can only be observed from the northern hemisphere. The Leo Minorids was only discovered in 1959, and is associated with the long period comet C/1739 K1 (Zanotti).


Being a new constellation created by Johannes Hevelius in 1687, there are no myths associated with it. In fact, Leo Minor is only one of ten constellations created by Hevelius, and he decided on the name “Leo Minor” only because the name relates to two of the constellations’ “beastly” neighbours, Ursa Major the Great Bear, and Leo, the Great Lion. However, in an attempt to shorten constellation names to make it easier to fit them onto star charts, English astronomer Richard Proctor renamed the constellation to Leaena, the Female Lion, in 1870, but the name was largely ignored by astronomers and cartographers of the time.

Although the modern constellation does not represent any Greek or Roman mythological characters in western tradition, there is some evidence to suggest that it did represent four celestial judges or advisors in Chinese mythology, and a “Gazelle with her Young” in Arabian astronomy.