HR 178

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

Template:Short description

HR 178
Observation data
Epoch J2000      Equinox J2000
Constellation Andromeda[1]
Right ascension Template:RA[2]
Declination Template:DEC[2]
Apparent magnitude (V) 6.046[3]
Characteristics
Evolutionary stage main sequence[4]
Spectral type kA5hF1mF2[5]
B−V Template:Engvar 0.287[3]
Variable type suspected[6]
Astrometry
Radial velocity (Rv)Script error: No such module "val".[7] km/s
Proper motion (μ) RA: Script error: No such module "val".[2] mas/yr
Dec.: Script error: No such module "val".[2] mas/yr
Parallax (π)8.0963±0.2630 mas[2]
DistanceTemplate:Rnd ± Template:Rnd ly
(Template:Rnd ± Template:Rnd pc)
Absolute magnitude (MV)+0.55[1]
Orbit[8]
Period (P)21.26 yr
Semi-major axis (a)0.126″
Eccentricity (e)0.5
Details
Mass2.44[9] Template:Solar mass
Radius3.82[2] Template:Solar radius
Luminosity45[2] Template:Solar luminosity
Surface gravity (log g)Script error: No such module "val".[10] cgs
TemperatureScript error: No such module "val".[10] K
Metallicity [Fe/H]Script error: No such module "val".[10] dex
Rotational velocity (v sin i)18[5] km/s
Age1.1[11] Gyr
Metallicity [Fe/H]{{{metal_fe2}}} dex
Other designations
HIP 3269, HD 3883, BD+23°94, SAO 74200
Database references
SIMBADdata

Script error: No such module "Check for unknown parameters".

HR 178 is a probable binary star in the constellation Andromeda. Located approximately Script error: No such module "convert". distant, it is an evolved Am star[4] with a combined apparent magnitude of 6.06, meaning that it can only be seen with the naked eye on dark, clear nights. The star is suspected of variability, possibly varying between magnitudes 6.04 and 6.06.[6] The variable magnitude period of HD 3883 is about 9.17 min.[12]

The spectrum of HR 178 has been extensively studied for establishing element abundances in the evolved Am stars. It is given a spectral class of kA5hF1mF2, meaning its spectral type is A5, F1, or F2, depending on the particular spectral lines examined. It is very close to the end of its main sequence evolution and the margin of error in its mass is only about Template:Solar mass.[4]

HR 178 has been suspected of being a binary star since 1938 when its spectrum was interpreted as being composite.[13] The pair were resolved using speckle interferometry in 1983.[14] The companion is modelled to be between 1.5 and 3 magnitudes fainter than the primary star.[15] Although there have since been several failed attempts to resolve the pair, a tentative orbit has been calculated with a period of 21.26 years and an eccentricity of 0.5.[8]

References

<templatestyles src="Reflist/styles.css" />

  1. ↑ a b Template:Cite XHIP
  2. ↑ a b c d e f g Template:Cite DR2
  3. ↑ a b Script error: No such module "citation/CS1".
  4. ↑ a b c Script error: No such module "Citation/CS1".
  5. ↑ a b Script error: No such module "Citation/CS1".
  6. ↑ a b Script error: No such module "citation/CS1".
  7. ↑ Script error: No such module "citation/CS1".
  8. ↑ a b Script error: No such module "Citation/CS1".
  9. ↑ Script error: No such module "Citation/CS1".
  10. ↑ a b c Script error: No such module "citation/CS1".
  11. ↑ Script error: No such module "Citation/CS1".
  12. ↑ Script error: No such module "citation/CS1".
  13. ↑ Script error: No such module "Citation/CS1".
  14. ↑ Script error: No such module "Citation/CS1".
  15. ↑ Script error: No such module "Citation/CS1".

Script error: No such module "Check for unknown parameters".

Template:Stars of Andromeda

Retrieved from "http://debianws.lexgopc.com/wiki143/index.php?title=HR_178&oldid=6916092"