ST Camelopardalis

ST Camelopardalis

The visual band light curve of ST Camelopardalis, from AAVSO data[1]
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Camelopardalis
Right ascension 04h 051m 13.348s[2]
Declination +68° 10′ 07.65″[2]
Apparent magnitude (V) 6.3 to 8.5[3]
Characteristics
Evolutionary stage Carbon star
Spectral type C5,4(N5)[3]
B−V color index +2.1[4]
Variable type SRb[3]
Astrometry
Proper motion (μ) RA: −2.992±0.136[2] mas/yr
Dec.: −3.237±0.185[2] mas/yr
Parallax (π)1.6725 ± 0.0989 mas[2]
Distance2,000 ± 100 ly
(600 ± 40 pc)
Absolute magnitude (MV)−1.232[5]
Details
Radius244[6] R☉
Luminosity4,478[2] L☉
Temperature3,388[6] K
Metallicity [Fe/H]−0.1[7] dex
Other designations
ST Camelopardalis, ST Cam, HD 20243, HIP 22552, BD+67°350
Database references
SIMBADdata

ST Camelopardalis, abbreviated ST Cam, is a carbon star in the constellation of Camelopardalis. It has a radius of 244 R☉.[6]

In 1902, Thomas William Backhouse announced that ST Cam was a low amplitude variable star with a long or irregular period.[8] It was given its variable star designation in 1912.[9]

ST Cam is a semiregular variable star. It is doubly periodic, with the two pulsation periods P0 and P1 being equal to 368.6 and 201 days respectively.[10]

ST Cam is an AGB star, in the process of expelling its red giant envelope into space.[11] Line emission from the 115 GHz rotational transition of carbon monoxide was detected in 1987 by Olofson et al. The width of the emission line indicated that ST Cam is surrounded by a circumstellar envelope expanding at 10 km/sec.[12] Bergeat and Chevallier (2005) analyzed later molecular spectroscopy results, and derived an envelope expansion velocity of 9 km/sec, and a mass loss rate of 1.1 × 10−6 M☉ per year.[11] Broadband emission from dust in the envelope was spatially resolved by the IRAS satellite in its 60 micron data. Dust was detected out to a distance of 3.1 arc minutes from the star, or about 1.8 light years assuming a distance to ST Cam of 600 pc.[13]

  1. ^ Cite error: The named reference aavso was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference Gaia DR2 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference gcvs was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference akari was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference gontcharov2011 was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference tess was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference lambert1986 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Backhouse was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference VSD was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference howarth2001 was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference Bergeat was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Olofsson was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Young was invoked but never defined (see the help page).