Ursa Minor, the Little Bear

Nomenclature

• Latin: Ursa Minor
• Genitive: Ursae Minoris
• Abbreviation: UMi
• Greek: Ἄρκτος Μικρά Arktos Mikra
• Arabic: al-Dubb al-Aṣġar

The mythological association for the constellation involves a bear, and so by comparison with the similarly-shaped Greater Bear these stars became known as the Lesser Bear. The Arabic, Latin, and Greek names all reflect this.

Description

Ursa Minor, the Little Bear, is the most northerly of the 88 modern constellations. The North Celestial Pole (NCP) lies within its borders just under one degree from its brightest star Polaris (α UMi). Other than the stars Polaris (α), Kochab (β), & Pherkad (γ²) UMi, the constellation is rather dim. Nevertheless, its stars are remarkable in that they resemble the figure of the Greater Bear, and so in many stories they go along together.

It is hard to mention Ursa Minor in the modern day without mentioning the Little Dipper, an asterism composed of Polaris (α), Kochab (β), Pherkad (γ²), Yildun (δ), ε, ζ, & η UMi. Unlike its counterpart the Big Dipper, it is hard to make it out in more light-polluted regions. As such, we tend to locate Polaris not by the shape of the Little Dipper but rather by the Pointers, Merak (β) & Dubhe (α) UMa. We can also use the Three Guides Algenib (γ Peg), Alpheratz (α And), & Caph (β Cas) to locate Polaris, and thus orient ourselves northwards.

Mythology

Cynosura

Aglaosthenes in his Naxica wrote that Ursa Minor was Κυνόσουρα Cynosura, as cited by Hyginus in Astronomica and Ps-Eratosthenes in Epitome to Catasterismi. This association was echoed by Aratus in Phaenomena. The authors posited that she and her sister Ἑλικη Helice were nurses of Zeus, and that they were entrusted with this role by Rhea to protect him from his cannibalistic father Cronus. They were aided in this task by the Κουρητες Curetes, whose clashing of spear and shield outside of the cave masked the sound of the infant's wails. Cynosura and Helice nursed Zeus on honey and the milk of the she-goat Αμαλθεια Amalthea, who is represented in the sky by the star Capella (α Aur). For this, they were also called Μελιαι Meliai, '[nymphs] of honey', by Callimachus, who also gave them the names Ιδη Ida, 'of Mount Ida', and Αδραστεια Adrasteia, 'not running-away, or stalwart', respectively.

In one tale, to hide from his father Cronus, Zeus transformed himself into a dragon and Cynosura and Helice into two bears. After the Titanomachy, to honour them for their rearing of him, Zeus fixed the ursine forms of the nymphs near the North Celestial Pole, both flanking himself as the Dragon which he placed in the sky as well (see also Draco, Ursa Major).

The names Cynosura and Helice very likely derived from the astral association rather than from any mythological association. Cynosura means 'dog's tail' in Greek, alluding the shape of Ursa Minor. Helice is a name meaning 'one that circles' in Greek, alluding to circles that the circumpolar Ursa Major traced across the night sky.

Phoenice

An alternative Greek name for the constellation was Φοινίκη Phoenice as noted by Aratus, Ps-Eratosthenes, and Hyginus. Aratus explained that the Greeks used the constellation Helice, or Ursa Major, to mark north while on voyage, while the Phoenicians used Cynosura, or Ursa Minor, elucidating the origin of the name Phoenice for the constellation. Hyginus expounded this claim, stating that it was Thales of Miletus, a Phoenician, that described Ursa Minor as a better indicator of north.

Ps-Eratosthenes also mentioned that the constellation was Phoenice, but used quite confusing language to describe it. He said that Phoenice was a huntress of Artemis and slept with Zeus, and that upon Artemis's discovery of the affair she turnt Phoenice into a bear. Later, to commemorate her rescue, she was placed a second time in the sky to give her double honor. In a vacuum, Ps-Eratosthenes seems to claim the maiden's name was Phoenice. However, it is ikely that they just conflated the story of Callisto's transformation and catasterism (see Ursa Major) with Ursa Minor, and then mentioned the name Phoenice as it was what they knew it as, essentially saying that [the constellation] Phoenice is [the character] Callisto, and that she was placed in the sky twice (as both celestial bears) to honour her doubly.

Hamaxa

The Greeks also knew this constellation as Ἄμαξα Hamaxa, 'wain, or wagon', as noted by Aratus and Germanicus Caesar. However, it is likely that the moniker was originally only for Ursa Major. The name originated from the shape of the figure and by association with the Ox-Driver constellation Boötes which trails it, and was likely transferred to the stars of Ursa Minor as the two bears' brightest stars take on very similar shapes.

Asterisms

• Little Dipper
• Guardians of the Pole
• Choreutae

Sources

1. Ridpath, Ian. Star Tales. link.
2. Lafitte, Roland. Catalogue of Star Names Created in the Greco-Arabian Sky. link.
3. Grant, Mary. The Myths of Hyginus (1960). link.
4. Condos, Theony. Star Myths of the Greeks and Romans: A Sourcebook (1997), pp. 201-204. link.
5. Hard, Robin. Eratosthenes and Hyginus, Constellation Myths with Aratus's 'Phaenomena' (2015), pp. 56-61, 295. link.
6. Kidd, Douglas. Aratus: Phaenomena (1997), pp. 75. link.
7. Gain, D. B. The Aratus Ascribed to Germanicus Caesar (1976), pp. 53-54. link.
8. IAU WGSN. IAU-Catalog of Star Names (CSN). link.
9. Stellarium Contributors. Stellarium Astronomy Software. link.