Astronomy   View all facts   Glossary   Help
physical object > naked eye object > naked eye star > Polaris
Next binary star: RS CVn star    Up: binary star, F star, naked eye star, Population I Cepheid, supergiant    Previous binary star: Mira   

Polaris
(HR 424, Pole star, North Star)
subjectfact 
Polarishas declination +89 15 512001-09-27 09:31:43.0
has right ascension 2 31 50.52001-09-27 09:31:43.0
has period 3.97 dayshas source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:31:43.0
has primary F8 Ib2001-09-27 09:31:43.0
has spectral type F7:Ib-IIv2001-09-27 09:31:43.0
has V magnitude 2.022001-09-27 09:31:43.0
is a part of Ursa Minorhas URL: http://www.seds.org/Maps/Const/Data/ursaminor_tab.html, 2001-09-27 09:31:42.0
has distance 330 light-yearshas source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:31:43.0
has synonym HR 4242001-09-27 09:31:42.0
has synonym Pole starhas source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:31:42.0
has synonym North Starhas source: Croswell, K. 1995 The Alchemy of the Heavens, Anchor Books, 2001-09-27 09:31:43.0
has synonym alpha UMihas source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:31:43.0
has B-V magnitude 0.602001-09-27 09:31:43.0
has use The star that lies near the direction in the sky toward which the North Pole of the Earth points.has source: Ferris, T. 1988 Coming of Age in the Milky Way, Morrow, 2001-09-27 09:31:42.0
has definition A supergiant F8 Ib, F3 V visual binary, with an orbital period of thousands of years. The primary (a Cepheid with a pulsation period of 3.97 days) is itself a single-lined spectroscopic double with a period of 29.6 years. There are at least two more faint (12th mag) components of the system.has source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:31:42.0
is an instance of Population I Cepheidhas source: Hopkins, J. 1976 Glossary of Astronomy and Astrophysics, University of Chicago Press, 2001-09-27 09:31:42.0
is an instance of F star2001-09-27 09:31:42.0
is an instance of supergiant2001-09-27 09:31:42.0
is an instance of naked eye star2001-09-27 09:31:42.0
is an instance of binary star2001-09-27 09:31:42.0
F starhas color yellow-white2001-09-27 09:30:46.0
has surface temperature 6000 to 7500 K2001-09-27 09:30:46.0
naked eye starhas been observed for many centuries2001-09-27 09:30:25.0
is usually part of asterism2001-09-27 09:30:25.0
is a part of celestial sphere2001-09-27 09:30:25.0
is a part of Milky Way2001-09-27 09:30:25.0
has apparent magnitude brighter than 52001-09-27 09:30:25.0
binary starhas number of stars 22001-09-27 09:30:54.0
has orbital period2001-09-27 09:30:31.0
Population I Cepheidhas absolute magnitude <Mv> = -0.5 to -62001-09-27 09:30:38.0
supergianthas luminosity class I2001-09-27 09:30:50.0
starhas star surface temperature2001-09-27 09:30:25.0
has B magnitude2001-09-27 09:30:25.0
has U magnitude2001-09-27 09:30:25.0
has position on celestial sphere from the point of view of Earth2001-09-27 09:30:25.0
has parallax from the point of view of Earth's orbit2001-09-27 09:30:25.0
has proper motion2001-09-27 09:30:24.0
has radiation at surface which is diffused out from the hotter core2001-09-27 09:30:24.0
has energy source gravitational contraction and or fusion2001-09-27 09:30:24.0
has energy production which takes place primarily within the core2001-09-27 09:30:24.0
has surface density which depends on luminosity class2001-09-27 09:30:24.0
has age2001-09-27 09:30:25.0
has catalog star catalog2001-09-27 09:30:25.0
has material hydrogen, helium2001-09-27 09:30:24.0
has velocity determined from proper motion and radial velocity2001-09-27 09:30:25.0
has mass greater than 0.08 the sun's mass2001-09-27 09:30:24.0
star systemhas abundance half the stars in the solar neighborhood are members of star systems2001-09-27 09:30:54.0
Population I starhas author Baade (1944)2001-09-27 09:30:27.0
is a part of disk2001-09-27 09:30:26.0
Cepheidhas prototype delta Cephei2001-09-27 09:30:38.0
celestial bodyhas spectra2001-09-27 09:30:09.0
physical objecthas location or center of gravity2001-09-27 09:27:27.0
has angular momentum2001-09-27 09:27:27.0
has momentum2001-09-27 09:27:27.0
has temperature2001-09-27 09:27:27.0
has volume2001-09-27 09:27:27.0
has extent2001-09-27 09:27:27.0
variablehas name designated with
  1. R, S, T, U, V, W, X, Y, or Z and the genitive of the latin constellation name
  2. 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
  3. 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
  4. V 335, V 336, etc., when the double letter designations are exhausted
2001-09-27 09:30:34.0
has observational problem some difficulty in distinguishing between various kinds2001-09-27 09:30:34.0
has observable variation time scale within a period of decadeshas URL: http://www.aavso.org, 2001-09-27 09:30:34.0
has light curve2001-09-27 09:30:34.0
has optical brightness variation 0.2 magnitudes or greater2001-09-27 09:30:34.0
has amplitude2001-09-27 09:30:34.0

Next binary star: RS CVn star    Up: binary star, F star, naked eye star, Population I Cepheid, supergiant    Previous binary star: Mira