R Hydrae

The bow shock around R Hya [1]
R Hydrae
Observation data
Epoch J2000      Equinox J2000
Constellation Hydra
Right ascension 13h 29m4 2.80s
Declination -23° 16' 53.0"
Apparent magnitude (V) 3.5 to 10.9 (variable)[2]
Characteristics
Spectral type M6e/M9e:
B−V color index 1.3
Variable type Mira
 period= 388.87 days[2]
Astrometry
Radial velocity (Rv)−10.4[3] km/s
Parallax (π)8.05 ± 0.69 mas
Distance410 ± 30 ly
(120 ± 10 pc)
Details
Mass2[4] M
Radius460 (variable)[4] R
Luminosity10,000 (variable)[4] L
Temperature2,830[4] K

R Hydrae, also known as R Hya,[2] is a Mira-type variable star in the constellation Hydra.[2][3]

The magnitude of R Hydrae varies over a period of 389 days, between 3.21 and 11.00. The period of R Hydrae changes slowly.

At maximum brightness the star can be seen with the naked eye, while at minimum a telescope of at least 5 cm is needed.

R Hydrae is approximately 2000 light years from Earth. R Hydrae's spectral class is M7IIIe.[3]

References

  1. Spitzer Science Center Press Release: Red Giant Plunging Through Space
  2. 2.0 2.1 2.2 2.3 AAVSO
  3. 3.0 3.1 3.2 SIMBAD
  4. 4.0 4.1 4.2 4.3 Zijlstra, A. A.; Bedding, T. R.; Mattei, J. A. (2002). "The evolution of the Mira variable R Hydrae". Monthly Notices of the Royal Astronomical Society 334 (3): 498. arXiv:astro-ph/0203328. Bibcode:2002MNRAS.334..498Z. doi:10.1046/j.1365-8711.2002.05467.x.

External links