Eta Sculptoris

Eta Sculptoris
Location of η Sculptoris (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Sculptor
Right ascension 00h 27m 55.69820s[1]
Declination −33° 00′ 25.7900″[1]
Apparent magnitude (V) 4.8 - 4.9[2]
Characteristics
Evolutionary stage asymptotic giant branch[3]
Spectral type M4III[4]
U−B color index +1.81[5]
B−V color index +1.64[5]
Variable type SRS[2]
Astrometry
Radial velocity (Rv)+12.1±1.7[6] km/s
Proper motion (μ) RA: −20.349[1] mas/yr
Dec.: −49.911[1] mas/yr
Parallax (π)7.0975 ± 0.2769 mas[1]
Distance460 ± 20 ly
(141 ± 5 pc)
Absolute magnitude (MV)−0.83[7]
Details
Radius79.96+3.70
−9.85[1] R☉
Luminosity1,012.3±44.6[1] L☉
Temperature3,641+247
−82[1] K
Other designations
η Scl, CD−33°152, FK5 2026, GC 544, HD 2429, HIP 2210, HR 105, SAO 192545, GSC 06994-01104
Database references
SIMBADdata

Eta Sculptoris, Latinized from η Sculptoris, is a single,[8] variable star in the central part[9] of the southern constellation of Sculptor. It is visible to the naked eye as a faint, red-hued star with an apparent visual magnitude that fluctuates around 4.81.[5] The star is located approximately 460 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +12 km/s.[6]

A light curve for Eta Sculptoris, plotted from MASCARA data folded with the best-fit period of 24.22 days[10]

This object is an aging red giant star,[4] currently on the asymptotic giant branch,[3] with a stellar classification of M4III.[4] With the supply of hydrogen at its core exhausted, the star has cooled and expanded. It now has 80 times the radius of the Sun.[1] Eta Sculptoris is classified as a semiregular variable with a visual magnitude that fluctuates between +4.80 and +4.90,[2] The pulsations have periods of 22.7, 23.5, 24.6, 47.3, 128.7 and 158.7 days.[11] On average, this star is radiating over a thousand times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 3,641 K.[1]

  1. ^ a b c d e f g h i j Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c Cite error: The named reference AAVSOR was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Eggen1992 was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference Hoffleit1991 was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference Ducati2002 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference XHIP was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference mnras389_2_869 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Streicher2008 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference MASCARA was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference tabur was invoked but never defined (see the help page).