Aries is a rather inconspicuous northern constellation and sign of the zodiac, which honors the ram whose golden fleece was sought by Jason and the Argonauts. Aries used to contain the vernal equinox, the point where the Sun crosses the celestial equator. Nowadays the vernal equinox has moved in the constellation Pisces, but sometimes it is still called the first point of Aries. The constellation can be seen from latitudes between +90° and -60°, and is best visible in the winter sky. The spring equinox, March 21, is the beginning of the new zodiacal year and Aries, the first sign, is therefore that of new beginnings.
Aries is devoid of prominent deep sky objects, and has only a few stars of interest, notably the triangle made up of the principal stars in the constellation. Aries is a nice constellation to view in the autumn and winter sky. The sun passes through it from late April to mid-May. Although there are not many objects to observe in Aries this constellation is important to astronomers. In former times the vernal equinox (i.e. the point where the Sun crosses the celestial equator when moving from the south to the north) lies within Aries, but due to the effect of precession this point is nowadays located in the western neighbor Pisces. For historical reasons the vernal equinox is still referred as the First Point of Aries. The meaning of this point is equal to the meaning of the null meridian at Greenwich: it is the zero point of the right ascension. This constellation can be found between DECL=+10 degrees and DECL=+30 degrees and between RA=1h 40m and RA=3h 30m, respectively. Over the body of Aries another asterism (pattern of stars seen in Earth's sky which is not an official constellation) is located - the Northern Fly hovers over Aries.
Aries is devoid of prominent deep sky objects, and has only a few stars of interest, notably the triangle made up of the principal stars in the constellation. Aries is a nice constellation to view in the autumn and winter sky. The sun passes through it from late April to mid-May. Although there are not many objects to observe in Aries this constellation is important to astronomers. In former times the vernal equinox (i.e. the point where the Sun crosses the celestial equator when moving from the south to the north) lies within Aries, but due to the effect of precession this point is nowadays located in the western neighbor Pisces. For historical reasons the vernal equinox is still referred as the First Point of Aries. The meaning of this point is equal to the meaning of the null meridian at Greenwich: it is the zero point of the right ascension. This constellation can be found between DECL=+10 degrees and DECL=+30 degrees and between RA=1h 40m and RA=3h 30m, respectively. Over the body of Aries another asterism (pattern of stars seen in Earth's sky which is not an official constellation) is located - the Northern Fly hovers over Aries.
Aucun commentaire:
Enregistrer un commentaire