Astronomy   View all facts   Glossary   Help

physical object > natural object > celestial body > collection of stars > star system > binary star > close binary > eclipsing binary > Vela X-1

Vela X-1 (HD 77581, 3U 0900-40)
subject			fact

Vela X-1	has spectral type B0.5 Ib
	has apparent magnitude 7
	has synonym HD 77581
	has synonym 3U 0900-40
	has orbital period 8.96 days
	has mass of unseen companion 1.7 to 15 Msun, with a probable value of about 2.6 Msun.
	is an instance of X-ray source
	is an instance of B star
	is an instance of supergiant
	is an instance of eclipsing binary
	is an instance of single line spectroscopic binary
eclipsing binary	has eclipse duration
B star	has color blue-white
	has surface temperature 11000 to 28000 K
	has absorption line He I
supergiant	has luminosity class I
X-ray source	has wavelength X-ray
	is a part of celestial sphere
periodic variable	has period
star	has star surface temperature
	has V magnitude
	has B magnitude
	has U magnitude
	has position on celestial sphere from the point of view of Earth
	has parallax from the point of view of Earth's orbit
	has proper motion
	has radiation at surface which is diffused out from the hotter core
	has energy source gravitational contraction and or fusion
	has energy production which takes place primarily within the core
	has surface density which depends on luminosity class
	has absolute magnitude
	has age
	has catalog star catalog
	has material hydrogen, helium
	has velocity determined from proper motion and radial velocity
celestial body	has spectra
binary star	has number of stars 2
variable	has name designated with R, S, T, U, V, W, X, Y, or Z and the genitive of the latin constellation name RR, RS, RT, RU, RV, RW, RX, RY, or RZ and the genitive of the latin constellation name when the single letter designations are exhausted AA...AZ, BB...BZ, etc. (omitting J), which ends with QQ...QZ and the genitive of the latin constellation namewhen the RR...RZ designations are exhausted V 335, V 336, etc., when the double letter designations are exhausted
	has observational problem some difficulty in distinguishing between various kinds
	has observable variation time scale within a period of decades
	has light curve
	has optical brightness variation 0.2 magnitudes or greater
	has amplitude
star system	has abundance half the stars in the solar neighborhood are members of star systems
physical object	has location or center of gravity
	has angular momentum
	has momentum
	has temperature
	has volume
	has extent

Next B star: Achernar    Up: B star, eclipsing binary, single line spectroscopic binary, supergiant, X-ray source    Previous B star: Spica