✦ Sagittarius (Sgr)
✦ Sagittarius (Sgr)
Subfolder of: Fixed Stars · Constellations
| Field | Value |
|---|---|
| IAU name | Sagittarius |
| IAU abbreviation | Sgr |
| Latin genitive (used in Bayer names) | Sagittarii |
| Zodiacal constellation | Yes |
| Ptolemaic constellation | Yes — one of Ptolemy’s 48 (Almagest VII–VIII) |
Constellations are not the same as the tropical signs: the signs are 30° divisions measured from the March equinox, while constellations are IAU sky regions of unequal size. Precession has moved the constellations roughly one sign-width against the tropical zodiac since antiquity.
Vault stars in Sagittarius
| Star | Designation | λ J2000.0 | λ 2026.0 | V mag |
|---|---|---|---|---|
| Spiculum | NGC 6530 (open cluster in the Lagoon Nebula, M8) | 1°01′ Capricorn | 1°23′ Capricorn | 4.6 |
| Kaus Media | δ Sagittarii | 4°34′ Capricorn | 4°56′ Capricorn | 2.668 |
| Kaus Australis | ε Sagittarii | 5°04′ Capricorn | 5°26′ Capricorn | 1.85 |
| Kaus Borealis | λ Sagittarii | 6°18′ Capricorn | 6°40′ Capricorn | 2.81 |
| Facies | Messier 22 (globular cluster) | 8°18′ Capricorn | 8°40′ Capricorn | 6.17 |
| Ascella | ζ Sagittarii | 13°37′ Capricorn | 13°59′ Capricorn | 2.585 |
Sources
- IAU, The Constellations (88 official constellations, abbreviations): https://www.iau.org/public/themes/constellations/
- Swiss Ephemeris fixed-star catalogue
sefstars.txt(ICRS/Hipparcos-based positions, proper motions, magnitudes): https://github.com/aloistr/swisseph/blob/master/ephe/sefstars.txt — ecliptic longitudes computed for this vault with Astropy 8.0 (GeocentricMeanEcliptic, mean equinox of J2000.0 and of 2026-01-01) - Ptolemy, Almagest VII–VIII (star catalogue of 48 constellations), trans. G. J. Toomer (1984)