R Andromedae

R Andromedae
Location of R Andromedae (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Andromeda
Right ascension 00h 24m 01.946s[1]
Declination +38° 34′ 37.37″[1]
Apparent magnitude (V) 5.8 - 15.2[2]
Characteristics
Spectral type S3,5e-S8,8e(M7e)[2]
B−V color index 1.97[3]
Variable type Mira[2]
Astrometry
Radial velocity (Rv)−6.40 [4] km/s
Proper motion (μ) RA: −16.021±0.148[1] mas/yr
Dec.: −32.794±0.141[1] mas/yr
Parallax (π)2.6444 ± 0.1600 mas[1]
Distance1,230 ± 70 ly
(380 ± 20 pc)
Absolute magnitude (MV)−5.19[5]
Details
Radius476±120 - 493±129[6] R☉
Luminosity6,300[7] L☉
Surface gravity (log g)−1.02[8] cgs
Temperature2,500[8] K
Metallicity [Fe/H]−1.01[9] dex
Other designations
HR 90, BD +37°58, HD 1967, SAO 53860, HIP 1901.
Database references
SIMBADdata

R Andromedae (R And) is a Mira-type variable star in the constellation Andromeda. Its spectral class is type S because it shows absorption bands of zirconium monoxide (ZrO) in its spectrum. It was among the stars found by Paul Merrill to show absorption lines of the unstable element technetium,[10] establishing that nucleosynthesis must be occurring in stars. The SH molecule was found for the first time outside earth in the atmosphere of this star.[11] The star is losing mass due to stellar winds at a rate of 1.09×10−6 M☉/yr.[5]

  1. ^ a b c d e Cite error: The named reference edr3 was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference gcvs was invoked but never defined (see the help page).
  3. ^ "R And". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved October 7, 2018.
  4. ^ Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Guandalini2010 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference van Belle1997 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference ramstedt was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference ortiz was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference gaspar was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference merrill1952 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Yamamura2000 was invoked but never defined (see the help page).