Psi Sagittarii

Psi Sagittarii

Location of ψ Sagittarii (circled)
Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Sagittarius
Right ascension	19h 15m 32.4s
Declination	−25° 15′ 24″
Apparent magnitude (V)	+4.86
Distance	330 ± 37 ly (101 ± 11 pc)
Spectral type	K0III + A8V
Other designations
ψ Sagittarii, ψ Sgr, Psi Sgr, 42 Sagittarii, CCDM J19155-2515A, CPD−27 6737, GC 26516, HD 179950, HIP 94643, HR 7292, PPM 269531, SAO 187882, WDS J19155-2515A.

Psi Sagittarii (Psi Sgr, ψ Sagittarii, ψ Sgr) is a binary star in the constellation Sagittarius. The star system is 330 light years from Earth. The two stars are separated by 0.15 arcseconds on the sky, which puts them approximately 15 astronomical units apart. The star system has a combined apparent magnitude of +4.86. The orbital period of the system is 18.8 years.

The two components have similar luminosities, with apparent magnitudes of +5.6 and +5.7. Stellar classification is somewhat uncertain. The stars have been classified as either a type A8 dwarf with a type G8 or K0 giant companion, or else a type F2 dwarf with an F7 giant companion.

Name and etymology

• According to the catalogue of stars in the Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars, this star was titled as Al Kiladah.
• This star, together with τ Sgr, ν Sgr, ω Sgr, 60 Sgr and ζ Sgr were Al Udḥiyy, the Ostrich's Nest.