See also: Arrow
HistoryThe Arrow is one of the constellations indexed by Ptolémée, even if it were then much smaller (approximately 4 square degrees).
Observation of stars; Location of the constellation The Arrow is in the Triangle of summer, in the North of the constellation of the Aigle. It is halfway between the head of the Cygne and Véga.
; Form constellation The Arrow is a weak constellation (mag 4) but of form rather characteristic, formed of four stars in alignment. More in the East (γ Sge) is most brilliant. That of the medium (δ Sge) is hardly less brilliant than the first. The empennage of the Arrow is less brilliant (mag 4), and is made of α and β Sge.
; Entourage The constellation is surrounded by weak small groups which populate the triangle of summer. Northern side, one sees the Petit Fox and the head of the Cygne. South-eastern side, one locates the Dauphin easily.
See also: List of stars of the Arrow
α Sagittae (Sham)α Sagittae (Sham) is the only star of the constellation to bear a traditional name, but is however not most brilliant. With a Magnitude connect of 4,39, almost a fifth magnitude, it is even rather difficult to see. Besides Sham means the Arab arrow in and was used formerly to name the very whole constellation.
α Sagittae is a star Géante, 20 times broader than the Sun. From the spectral point of view, Sham is located in the “hole” of Hertzsprung-Russel, between stars of the principal sequence and giant stars.
γ Sagittaeγ Sagittae is the most luminous star of the constellation of the Arrow. Of a magnitude of 3,47 - finally not very brilliant -, γ Sagittae is a red giantess 55 times larger than the Sun having begun the fusion of sound Hélium in its core, composed of a mixture of Oxygène and Carbone.
Other starsNone of other stars of the constellation of the Arrow is very brilliant. δ Sagittae (magnitude 3,82) is a little less luminous than γ Sagittae, while β Sagittae resembles much Sham by the magnitude, the distance and the spectral type.
Celestial objectsThe constellation also shelters the globular Amas M71.
- List of stars of the Arrow
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