R Coronae Borealis

Starbox begin
name=R CrBStarbox image


caption = R Coronae Borealis Starbox observe
epoch=J2000
ra=RA|15|48|34.4149
dec=DEC|+28|09|24.296
appmag_v=5.9
constell=Corona Borealis Starbox character
class=G0Iab:pe
b-v=?
u-b=?
variable=Variable Star of R CrB type Starbox astrometry
radial_v=24.8
prop_mo_ra=-2.10
prop_mo_dec=-11.52
parallax=0.54
p_error=0.72
absmag_v=6.46 Starbox detail
mass=0.8
radius=?
luminosity=?
temperature=?
metal=?
rotation=?
age=? Starbox catalog
names= V* R CrB, GSC2 N1330022410, 2MASS J15483440+2809242, AG+28° 1513, GSC 02039-01605, N30 3552, TD1 18592, BD+28° 2477, HD 141527, PLX 3581, TYC 2039-1605-1, EM* CDS 886, HIC 77442, PPM 104338, GC 21257, HIP 77442, RAFGL 4219, YZ 28 7350, GCRV 9116, HR 5880, ROT 2225, AAVSO 1544+28A, IRAS 15465+2818, SAO 84015. Starbox reference
Simbad=R+Coronae+Borealis

R Coronae Borealis is a yellow supergiant star, and is the prototype of the RCB class of variable stars, which fade by several magnitudes at irregular intervals. R Coronae Borealis itself normally shines at approximately magnitude 6, just about visible to the naked eye, in the constellation of Corona Borealis, but at intervals of several months to many years fades to as faint as magnitude 14. Over successive months it gradually returns to its normal brightness, giving it the nickname "Fade-Out star," or "Reverse Nova".

The cause of this behaviour is believed to be a regular build-up of carbon dust in the star's atmosphere. The sudden drop in brightness may be caused by a rapid condensation of dust, resulting in much of the star's light being blocked. The gradual restoration to normal brightness results from the dust being dispersed by radiation pressure.

External links

* [http://www.seds.org/~spider/spider/Vars/rCrB.html SEDS page]
* [http://www.aavso.org/vstar/vsots/0100.shtml AAVSO page]
* [http://www.daviddarling.info/encyclopedia/R/R_Coronae_Borealis_star.html Entry in the Encyclopedia of Astrobiology, Astronomy, and Spaceflight]
* http://jumk.de/astronomie/special-stars/r-cor-bor.shtml
* [http://www.eso.org/public/outreach/press-rel/pr-2007/pr-34-07.html ESO 34/07 - Science Release: "Star Caught Smoking"]