subgiant Quick reference
A Dictionary of Astronomy (3 ed.)
... A star that has exhausted the hydrogen at its centre and is evolving into a giant. They are of luminosity class IV. The subgiants we see are usually less massive than the Sun, because more massive stars move very quickly through this stage into giants. Low-mass stars take many billions of years to evolve this far, so low-mass subgiants are very old. A subgiant branch on the Hertzsprung–Russell diagram, linking the main sequence to the giant branch, is therefore found only for old clusters such as globular...
subgiant Reference library
The New Oxford Dictionary for Scientific Writers and Editors (2 ed.)
... (not hyphenated) Astron. See giant...
subgiant
A star that has exhausted the hydrogen at its centre and is evolving into a giant. They are of luminosity class IV. The subgiants we see are usually less massive than the Sun, because more massive ...
Zubenelgenubi
The star Alpha Librae, magnitude 2.7. It is an A3 giant or subgiant 75 l.y. away. It has a wide companion of magnitude 5.2, an F3 dwarf.
Shaula
The star Lambda Scorpii, magnitude 1.6, a B1.5 subgiant 571 l.y. away. It is a variable Beta Cephei star, varying by about 0.05 mag. with a period of 5.1 hours.
Acamar
The star Theta Eridani, magnitude 2.9. It is a double star, consisting of an A5 subgiant and an A1 dwarf, magnitudes 3.2 and 4.3, 161 l.y. away.
Alioth
The star Epsilon Ursae Majoris. It is an A0 subgiant of magnitude 1.8 with strong lines of chromium in its spectrum. It is a variable of the Alpha2 Canum Venaticorum type, fluctuating by a few tenths ...
Algenib
The star Gamma Pegasi, a B2 subgiant of magnitude 2.8, lying 392 l.y. away. Algenib is also an alternative name for the star Mirfak (Alpha Persei).
Alpha Crucis
The brightest star in the constellation Crux, also called Acrux. It is a double star consisting of a B0.5 subgiant, magnitude 1.3, and a B1 dwarf, magnitude 1.7. To the naked eye they appear as a ...
Menkalinan
The star Beta Aurigae. It is an eclipsing binary consisting of a pair of A2 subgiants that varies between magnitudes 1.9 and 2.0 with a period of 3.96 days. It lies 81 l.y. away.
Merak
The star Beta Ursae Majoris, magnitude 2.3. It is an A0 subgiant or dwarf and lies 80 l.y. away. With Dubhe, it forms the Pointers that indicate the direction of the Pole Star, Polaris.
Procyon
The star Alpha Canis Minoris, magnitude 0.40, the eighth-brightest star in the sky. It is an F5 subgiant or dwarf and lies 11.5 l.y. away, among the nearest stars to us. Procyon has a white dwarf ...
R Canis Majoris star
A binary star with components of widely differing masses, and somewhat ambiguous spectral features. The type star is a semidetached Algol star, with a late-A-type primary (1.5 solar masses) and a ...
giant branch
The region of the Hertzsprung–Russell diagram that extends diagonally to the upper right of the main sequence, containing giant stars. The giant branch ranges from stars with a surface temperature ...
Alpheratz
The star Alpha Andromedae, magnitude 2.1. It is a B9 subgiant 97 l.y. away. An alternative name is Sirrah.
Delta Scuti star
A type of pulsating variable with a short period (0.01–0.2 day) and small amplitude (0.003–0.9 mag.); abbr. DSCT. The pulsation is driven primarily by instabilities in the hydrogen convection zone, ...
