T Andromedae

Not to be confused with τ Andromedae.
T Andromedae

A visual band light curve for T Andromedae, plotted from AAVSO data[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Andromeda
Right ascension 00h 22m 23.14956s[2]
Declination +26° 59′ 45.73676″[2]
Apparent magnitude (V) 7.70 – 14.30 variable [3]
Characteristics
Spectral type M4e-M7.5e[3]
B−V color index 2.63[4]
Variable type Mira[3]
Astrometry
Radial velocity (Rv)−90±10[4] km/s
Proper motion (μ) RA: −7.108[2] mas/yr
Dec.: −3.352[2] mas/yr
Parallax (π)0.5913 ± 0.0815 mas[2]
Distanceapprox. 5,500 ly
(approx. 1,700 pc)
Details
Mass4.9[5] M☉
Luminosity8.928[6] L☉
Surface gravity (log g)−0.51[5] cgs
Temperature3,235[5] K
Metallicity [Fe/H]−0.39[5] dex
Other designations
BD +26°43, HD 1795, SAO 73930
Database references
SIMBADdata

T Andromedae (T And) is a variable star of the Mira type in the constellation Andromeda. Like all the stars of this kind, T And is a cool asymptotic giant branch star of spectral type M4e-M7.5e. Its brightness varies periodically, completing a cycle in 281 days. The peak luminosity, however, is different every variability cycle, but can reach a peak magnitude mv=7.70.[3]

Thomas David Anderson discovered that T Andromedae is a variable star, in 1894.[7] The next year, Edward Charles Pickering examined archival photographic plates to derive a light curve for the star, and calculated a period of 281 days.[8]

Measurements of the angular size variations of T And made with the Palomar Testbed Interferometer show no clear correlation with the star's brightness variations.[9][10]

  1. ^ Cite error: The named reference aavso was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference dr3 was invoked but never defined (see the help page).
  3. ^ a b c d General Catalogue of Variable Stars, s.v. T. And.
  4. ^ a b "T And". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved October 8, 2018.
  5. ^ a b c d Cite error: The named reference starhorse2 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference dr2 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Espin1894 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Pickering1895 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Creech was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Thompson was invoked but never defined (see the help page).