Alpha Tucanae

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

Template:Short description

α Tucanae
Template:Location mark
Location of α Tucanae (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Tucana
Right ascension Template:RA[1]
Declination Template:DEC[1]
Apparent magnitude (V) 2.86[2]
Characteristics
Spectral type K3 III[3]
U−B Template:Engvar +1.54[2]
B−V Template:Engvar +1.39[2]
Astrometry
Radial velocity (Rv)+45.8[4] km/s
Proper motion (μ) RA: −77.000[1] mas/yr
Dec.: −32.823[1] mas/yr
Parallax (π)17.7324±0.3290 mas[1]
DistanceTemplate:Rnd ± Template:Rnd ly
(Template:Rnd ± Template:Rnd pc)
Absolute magnitude (MV)−1.05[5]
Absolute bolometric
magnitude (Mbol)		−1.97[5]
Orbit[6]
Period (P)4197.7 days
Eccentricity (e)0.39
Periastron epoch (T)18666.4
Argument of periastron (ω)
(secondary)		48.5°
Semi-amplitude (K1)
(primary)		7.2 km/s
Details
Mass2.5 - 3[7] Template:Solar mass
Radius37.3[8] Template:Solar radius
Luminosity424[7] Template:Solar luminosity
Temperature4310[8] K
Metallicity [Fe/H]{{{metal_fe2}}} dex
Other designations
Lang-Exster, CPD−60°7561, FK5 841, HD 211416, HIP 110130, HR 8502, SAO 255193[9]
Database references
SIMBADdata

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

Alpha Tucanae (α Tuc, α Tucanae), also named Lang-Exster,[10] is a binary star system in the southern circumpolar constellation of Tucana. With an apparent visual magnitude of 2.86,[2] it can be seen with the naked eye from the southern hemisphere. Using parallax measurements, the distance to this system can be estimated as Script error: No such module "convert".. A cool star with a surface temperature of 4300 K, it is 424 times as luminous as the sun and 37 times its diameter. It is 2.5 to 3 times as massive. It is unclear what stage of evolution the star is in.[7]

This is a spectroscopic binary, which means that the two stars have not been individually resolved using a telescope, but the presence of the companion has been inferred from measuring changes in the spectrum of the primary. The orbital period of the binary system is 4197.7 days (11.5 years).[6] The primary component has a stellar classification of K3 III,[3] which indicates it is a giant star that has exhausted the supply of hydrogen at its core and evolved away from the main sequence. It has the characteristic orange hue of a K-type star.

The IAU Working Group on Star Names approved the name Lang-Exster for this star system on 19 September 2024 and it is now so entered in the IAU Catalog of Star Names. "Lang" is a Malay and Indonesian word meaning hornbill, and "Exster" is a Dutch word meaning magpie; both were historically used as names for the constellation Tucana. Since this star is a binary system it is given a double name, making it the second star system with multiple IAU-named components, after Alpha Centauri.[10]

References

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

  1. ↑ a b c d e Template:Cite Gaia DR3
  2. ↑ a b c d Script error: No such module "citation/CS1".
  3. ↑ a b Script error: No such module "citation/CS1".
  4. ↑ 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. ↑ a b c 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 Script error: No such module "citation/CS1".

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

Template:Stars of Tucana

Retrieved from "http://debianws.lexgopc.com/wiki143/index.php?title=Alpha_Tucanae&oldid=1890357"