Costellazione Leone Minore, stelle principali e mitologia

30 Apr 2018

OSR blog post

Il Leone Minore, o Leoncino (in latino Leo Minor, abbreviato in LMi) è una piccola costellazione boreale, compresa in declinazione fra l'Orsa Maggiore e il Leone. Raffigurante un cucciolo di leone che si accompagna al Leone Maggiore, la sua stella più luminosa è Praecipua. La costellazione venne introdotta dall'astronomo polacco Johannes Havelius nel 1697.

Main stars

Since it is a small constellation, its main stars are relatively dim. Among them it is worth mentioning:
– 46 LMi (Praecipua), whose name means Main, considering the fact that it is the brightest star in the constellation. It is a subgiant star, located at a distance of 98 light years from Earth. A designation made by Bayer is missing (in the sense that, unlike other constellations, an Alpha star was not identified), which means that Leo Minor is the only constellation with a brighter star without a name .
– β LMi, giant binary star, whose components orbit each other with a 37-year cycle. Curiously, unlike 46 LMi, this star has a name, although it is not the brightest star in Leo Minor. It is the only binary system within the reach of commonly used observation instruments.

The constellation of Leo Minor is equipped with some variable stars, some of which can also be observed with simple binoculars: the best known among them is R Leonis Minoris, a gaseous Myreid; the RX Leonis Minoris, on the other hand, is a semi-regular variable, whose oscillations can also be visible to the naked eye, since its maximum brightness is 5.1 (while in the minimum phase it is barely perceptible).
The constellation also includes some objects in the deep sky, the observation of which, however, requires amateur instruments of a certain consistency; however, the absence of galactic dust within the constellation also makes it possible to observe numerous galaxies:
– Among the brightest we can mention NGC 3344, which appears as a foggy spot;
– Among other noteworthy objects is the so-called Hanny’s Voorwerp: discovered in 2007, it appears to be the remains of an accretion cloud that enveloped a quasar (extremely luminous galactic nucleus).

Mythology of Leo Minor

The constellation Leo Minor was introduced in 1690 by the Polish astronomer Johanness Hevelius, together with other minor constellations, in order to provide a classification to groups of stars without any grouping. However, unlike numerous other constellations introduced by Hevelius, Leo Minor has been recognized in the modern catalog of constellations, placing itself in 64th place among those with the largest extension, even preceding much more famous rivals such as the Dolphin, Canis Minor and the Corona Borealis. Being, therefore, a recently discovered constellation, it is not associated with any particular mythological event.
However, its name is inextricably linked to that of the nearby and major constellation of Leo: in fact, the introduction of the Little Lion was aimed, in fact, in order to give a puppy to the Greater Leo.
In this area of ​​the sky, the ancient Egyptians depicted Cancer: in fact, the zodiac present in the temple of Hathor of Dendera (modern Iunet, in Egypt), depicted this constellation , in a sandstone bas-relief (which is currently kept in the museum of Louvre), as being part of that of Cancer. However, according to the scholar RH Allen, due to a different tradition present in Egypt, these stars, together with the others that currently represent the legs of the Big Dipper (located a short distance away), were known by the ancient Egyptians as a Scarab (dung insect widespread along the Nile), drawn with the front legs extended.

Characteristics and observation

The poverty of bright stars makes identifying Leo Minor difficult. As mentioned, curiously this constellation does not have an Alpha star, although modern cataloging predicts a Beta star. This seems to have happened due to an oversight by Francis Baily, an English astronomer active in the 19th century: since Hevelius did not assign any name to the stars of the constellations he discovered and catalogued, this operation was carried out, precisely by Baily, over a century later; this scholar, however, assigned the letter Beta to the second brightest star of Leo Minor, without also naming the brightest. A name for this, however, seems to have been given, curiously, by Hevelius (as an exception to his disregard for this aspect), who according to the historian RH Allen, would have named it, precisely, Praecipua, or Main Star.

The constellation depicts a feline cub crouching down on its grandiose parent (Leo Major). However, the brightest stars, those that easily appear to the naked eye, also make it difficult to see the figure of the lion, since it is three stars arranged vertically.
Well, these three celestial bodies make up the back of the Little Lion. To proceed with their identification, you can move starting from the hind legs of the Big Dipper (the Lambda-Mi and Ni-Csi pairs), looking towards the south; Furthermore, Leo Minor is literally located above the back of Leo: more precisely, the constellation of Leoncino is located halfway between the so-called Sickle of the Lion (which identifies its back) and the hind legs of the Big Dipper.

The best period for night observation is between the months of January and June, as is the case for nearby Leone. The constellation crosses the meridian towards the end of winter, between the end of February and the beginning of March. It is a boreal constellation, which means that the observer located north of the equator has a great advantage in observation: however, not being a very northern constellation, it can be seen, albeit with some difficulties, even in the southern temperate.