| Meaning: | The Ram |
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Print out the star map from Sky and Telescope
Things to look for: Messier objects: Note: [x.x] indicates visual magnitude |
| Pronunciation: | air’ eeze | ||
| Associated Asterisms: | The Northern Fly | ||
| % of the sky: | 1.07% | ||
| Visible Stars: | 28 stars brighter than magnitude 5.5 |
Aries sits quietly between Pisces, Perseus and Taurus bounded above by Triangulum and below by Cetus. It contains no Messier objects and as such is often overlooked as a place the point telescopes; even the NGC objects within its bounds are dim but not necessarily without interest. It is a member of the zodiac and the Sun resides within its bounds from late April to mid May. The well known “First Point of Aries” no longer sits within the constellation due to precession and is now in Pisces and on its way into Aquarius in a few hundred years. Its named stars include Hamal α Ari, Sheratan β Ari, Mesarthim γ Ari and Botein δ Ari. Interestingly, the latter is dimmer than 41 Arietis which didn’t earn a name of its own.
Hamal comes from the Arabic word for “lamb” or “head of the ram” (ras al-hamal) and is an orange giant with a luminosity 96 times that of our Sun but appears magnitude 2 in our skies due to its 66 light year distance. Sheratan, is a blue-white star dimmer than Hamal a magnitude 2.64. Its name is derived from “sharatayn“, the Arabic word for “the two signs”. Mesarthim appears as a magnitude 3.9 star but, as discovered by Robert Hooke in 1664, it is a binary with two white-hued components. The origin of the name is not as clear cut as its siblings in the constellation. It may be from either of the Arabic words meaning “pair” or “fat ram” (al-sharatan) or perhaps from either the Sanskrit for “first star of Aries” or the Hebrew for “ministerial servants”. The two components are separated by 7.8 arcseconds. Robert Hooke found the pair whilst following a comet in a telescope.
Aries is not difficult to find due to the proximity of M45, the Pleiades and following M31 through Mirach (β And) down. The closeness of Hamal (α Ari) and Sheratan (β Ari) “the horns” makes positive identification easy.
The constellation contains the radiant of several meteor showers:
- Delta Arietids from 8 December to 14 January peaking on 9 December with a significant drop of from 14 December. The parent body source is believed to be a near-Earth asteroid 1990HA. The shower is associated with the occasional fireball.
- Autumn Arietids from 7 September to 27 October peaking on 9 October.
- Epsilon Arietids from 12 to 23 October.
Also the October Delta Arietids, Daytime Epsilon Arietids, Daytime May Arietids, Sigma Arietids, Nu Arietids and Beta Arietids.