RR Lyrae

Starbox begin
name=RR Lyrae Starbox image


caption = RR Lyrae Starbox observe
epoch=J2000
ra=19^h 25^m 27.9129^s
dec= +42° 47′ 03.696″
appmag_v=7.13
constell=Lyra Starbox character
class=F5
b-v=
u-b=
variable=Variable Star of RR Lyr type Starbox astrometry
radial_v=-72.4
prop_mo_ra=-109.59
prop_mo_dec= -195.54
parallax=4.38
p_error=0.59
absmag_v=7.29 Starbox detail
mass=?
radius=?
luminosity=? | temperature=?
metal=?
rotation=?
age=? Starbox catalog
names=V* RR Lyr, 2MASS J19252793+4247040, TD1 24704, AG+42° 1698, G 125-7, NLTT 47799, TYC 3142-494-1, AN 34.1901, GSC 03142-00494, NSVS 5543125, USNO-B1.0 1327-00425262, ASCC 425414, HD 182989, PLX 4550, USNO 886, BD+42° 3338, HIC 95497, PPM 58291, uvby98 100182989 V, GAT 791, HIP 95497, SAO 48421, GC 26836, LSPM J1925+4247, GCRV 11873, LTT 15677, SV* HV 180. Starbox reference
Simbad=HD+182989

RR Lyrae is a variable star in the Lyra constellation. It is the prototype of the RR Lyrae variables star class. It has a period of about 13 hours, and oscillates between apparent magnitudes 7 and 8. Its variable nature was discovered by the Scottish astronomer Williamina Fleming at Harvard Observatory in 1901. As RR Lyrae variables are important standard candles, knowing the precise distance of this star is necessary to determine its luminosity, and hence that of other stars in its class.

Its distance long uncertain, the Hubble Space Telescope's Fine Guidance Sensor was used in 2002 to determine the distance of RR Lyrae within ~5%: 262 parsecs, or 854 light-years. If accurate, this gives RR Lyrae an absolute magnitude of 0.61, nearly 49 times solar luminosity.

Location

References

*cite book
last = Burnham
first = Robert, Jr.
authorlink = Robert Burnham
coauthors =
title = Burnham's Celestial Handbook, Volume 2
publisher = Dover Publications
date = 1978
location = New York
pages =
url =
doi =
id = ISBN 0-486-23568-8
* [http://simbad.u-strasbg.fr/cgi-bin/cdsbib?2002AJ....123..473B Benedict, et al., "Astrometry with the Hubble Space Telescope: a parallax of the fundamental distance calibrator RR Lyrae"]
* [http://aladin.u-strasbg.fr/AladinPreview?-c=19+25+27.9129%2B42+47+03.696&ident=V*+RR+Lyr&submit=Aladin+previewer image RR Lyrae]

ee also

*RR Lyrae variable