Phi Cassiopeiae

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

Template:Short description

φ Cassiopeiae
Template:Location mark
Location of φ Cassiopeiae (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cassiopeia[1]
A
Right ascension Template:RA[2]
Declination Template:DEC[2]
Apparent magnitude (V) +5.11[3]
C
Right ascension Template:RA[4]
Declination Template:DEC[4]
Apparent magnitude (V) +7.08[3]
Characteristics
A
Spectral type F0Ia[3]
U−B Template:Engvar +0.49[5]
B−V Template:Engvar +0.68[5]
C
Spectral type B6Ib[3]
U−B Template:Engvar −0.37[5]
B−V Template:Engvar +0.41[5]
Astrometry
A
Radial velocity (Rv)−28.39[6] km/s
Proper motion (μ) RA: −1.479[2] mas/yr
Dec.: −1.231[2] mas/yr
Parallax (π)0.2142±0.0838 mas[2]
Distanceapprox. Template:Rnd ly
(approx. Template:Rnd pc)
Absolute magnitude (MV)−8.76[7]
C
Radial velocity (Rv)−28.50[8] km/s
Proper motion (μ) RA: −1.560[4] mas/yr
Dec.: −0.809[4] mas/yr
Parallax (π)0.3679±0.0169 mas[4]
DistanceTemplate:Rnd ± Template:Rnd ly
(Template:Rnd ± Template:Rnd pc)
Absolute magnitude (MV)−6.5[9]
Details
A
Mass6.3[10]–17[11] Template:Solar mass
Radius263[10] Template:Solar radius
Luminosity170,000[10] Template:Solar luminosity
Surface gravity (log g)1.0[7] cgs
Temperature7,341[7] K
Metallicity-0.24[7]
Rotational velocity (v sin i)23[12] km/s
Age20[13] Myr
C
Mass21[9] Template:Solar mass
Radius53[9] Template:Solar radius
Luminosity83,000[14] Template:Solar luminosity
Surface gravity (log g)2.05[14] cgs
Temperature15,500[14] K
Metallicity [Fe/H]{{{metal_fe2}}} dex
Rotational velocity (v sin i)35[14] km/s
Other designations
34 Cassiopeiae, HR 382, CCDM J01200+5813, ADS 1073
A: HD 7927, HIP 6242, BD+57°260, SAO 22191, GC 1594
C: HD 7902, HIP 6229, BD+57°257, SAO 22187, GC 1590, NSV 466
Database references
SIMBADdata

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

Phi Cassiopeiae (φ Cas, φ Cassiopeiae) is a multiple star in the constellation Cassiopeia with a combined apparent magnitude of +4.95. The two brightest components are A and C, sometimes called φ1 and φ2 Cas. φ Cas A is an F0 bright supergiant of magnitude 4.95 and φ Cas C is a 7.08 magnitude B6 supergiant at 134".

System

File:NGC 0457 DSS.jpg
φ1 and φ2 Cassiopeiae are the two brightest stars in the field of open cluster NGC 457.

φ Cassiopeiae appears among the stars of the open cluster NGC 457, which is at 2,400pc, but it is uncertain whether it is a member of the cluster.[13] φ Cas is generally treated as having five component stars, designated A to E in order of distance from the brightest star. The two components A and C are the brightest members of NGC 457; they are sometimes referred to as φ1 and φ2 Cassiopeiae.[15] Component B is a 12th magnitude star 49" from φ1. Components D and E and both 10th magnitude B-type main sequence stars in NGC 457, with component E only 42" from φ2. Another three components are sometimes listed as components of the multiple system, although this is somewhat arbitrary with dozens of members of NGC 457 being found within a few arc-minutes.[16]

The two supergiants share a similar space motion to the other stars in NGC 457, but their evolutionary status and brightness makes them unlikely members.[10] Their Gaia Data Release 2 parallaxes are comparable to other stars in the cluster and consistent with the accepted distance of NGC 457,[17] and component C has been given a 70% likelihood of being a member of the cluster.[18]

Properties

The primary component of the φ Cassiopeiae system is a very luminous yellow supergiant. Its absolute magnitude is comparable to some yellow hypergiants but it does not show the level of mass loss and instability that would qualify it as a hypergiant itself. Various model atmospheres all give a temperature around 7,300K, a low surface gravity, a radius around Template:Solar radius, and a luminosity well over Template:Solar luminosity. More uncertain is the mass, which would be expected to have been well over Template:Solar mass initially, but much less now. Different authors have published values from Template:Solar mass to Template:Solar mass.[10][11]

Component C is a relatively typical B class supergiant, 83,000 times the luminosity of the sun. It is a suspected variable and a suspected spectroscopic binary.[19]

See also

References

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

  1. ↑ Script error: No such module "Citation/CS1".
  2. ↑ a b c d e Template:Cite Gaia DR3
  3. ↑ a b c d Script error: No such module "Citation/CS1".
  4. ↑ a b c d e Template:Cite Gaia DR3
  5. ↑ a b c d Script error: No such module "Citation/CS1".
  6. ↑ Script error: No such module "Citation/CS1".
  7. ↑ a b c d Script error: No such module "Citation/CS1".
  8. ↑ Script error: No such module "Citation/CS1".
  9. ↑ a b c Script error: No such module "Citation/CS1".
  10. ↑ a b c d e Script error: No such module "Citation/CS1".
  11. ↑ a b Script error: No such module "Citation/CS1".
  12. ↑ Script error: No such module "Citation/CS1".
  13. ↑ a b Script error: No such module "Citation/CS1".
  14. ↑ a b c d Script error: No such module "Citation/CS1".
  15. ↑ Script error: No such module "citation/CS1".
  16. ↑ Script error: No such module "Citation/CS1".
  17. ↑ Template:Cite DR2
  18. ↑ Script error: No such module "Citation/CS1".
  19. ↑ Script error: No such module "Citation/CS1".

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

Template:Stars of Cassiopeia

Retrieved from "http://debianws.lexgopc.com/wiki143/index.php?title=Phi_Cassiopeiae&oldid=2846016"