6 Cassiopeiae

Last updated
6 Cassiopeiae
Cassiopeia constellation map.svg
Red circle.svg
Location of 6 Cassiopeiae (circled)
Observation data
Epoch J2000.0       Equinox J2000.0
Constellation Cassiopeia
Right ascension 23h 48m 50.171s [1]
Declination +62° 12 52.26 [1]
Apparent magnitude  (V)+5.43 [2] (5.34 - 5.45 [3] )
Characteristics
Spectral type A2.5 Ia+ [4]
U−B color index −0.02 [2]
B−V color index +0.67 [2]
Variable type α Cyg [3]
Astrometry
Proper motion (μ)RA: −3.57±0.35 [1]   mas/yr
Dec.: −1.57±0.33 [1]   mas/yr
Parallax (π)0.53 ± 0.37  mas [1]
Distance 2,510 [5]   pc
Absolute magnitude  (MV)−8.30 [6]
Details
Mass 22.0 [6]   M
Radius 193 [6]   R
Luminosity 200,000 [7]   L
Surface gravity (log g)1.59 [8]   cgs
Temperature 10,023±227 [8]   K
Metallicity [Fe/H]0.29 [8]   dex
Rotational velocity (v sin i)50 [6]  km/s
Other designations
6  Cas, V566  Cas, HR  9018, HD  223385, BD+61°2533, HIP  117447, SAO  20869
Database references
SIMBAD data

6 Cassiopeiae (6 Cas) is a white hypergiant in the constellation Cassiopeia, and a small-amplitude variable star.

Contents

System

6 Cassiopeiae A is a white A2.5 type hypergiant. It is about 25 times as massive as the Sun and 200,000 times as luminous. The star is slightly and erratically variable, an Alpha Cygni variable. Not all sources consider 6 Cas to be a hypergiant. It is thought that the "+" in an early A3 Ia+ spectral classification referred to indications of additional spectral features from a possible companion rather than the more modern indication of a hypergiant luminosity class. However, later publications have given more conventional hypergiant spectral types such as B9Ia+ and A3Ia+. [9]

A light curve for V566 Cassiopeiae from Hipparcos data, plotted as a function of phase assuming the dominant period found by Koen and Eyer (2002) V566CasLightCurve.png
A light curve for V566 Cassiopeiae from Hipparcos data, plotted as a function of phase assuming the dominant period found by Koen and Eyer (2002)

6 Cas A has a number of close companions, most notably an 8th magnitude O class bright giant at only 1.5 . Its spectral type is O9.75 and its absolute magnitude is −5.8. [12] Both are considered to be members of the Cassiopeia OB5 stellar association at a distance of around 8,000 light-years, [13] along with several other nearby stars. [14] Gaia parallaxes of the nearby stars suggest a mean distance to the association of about 9,000 light years. [14]

Variability

6 Cas A is an α Cyg variable, pulsating erratically between 5.34 and 5.45. The strongest period detected in one study was 37 days. [10] It has the variable star designation V566 Cassiopeiae. [3]

Related Research Articles

<span class="mw-page-title-main">Rho Cassiopeiae</span> Yellow hypergiant star in the constellation Cassiopeia

Rho Cassiopeiae is a yellow hypergiant star in the constellation Cassiopeia. It is about 8,150 light-years (2,500 pc) from Earth, yet can still be seen by the naked eye as it is over 300,000 times brighter than the Sun. On average it has an absolute magnitude of −9.5, making it visually one of the most luminous stars known. Its diameter measures between 636 and 981 times that of the Sun, approximately 1,125,000,000 kilometers, or almost four times the size of Earth's orbit.

<span class="mw-page-title-main">CS Camelopardalis</span> Binary star in the constellation Camelopardalis

CS Camelopardalis is a binary star in reflection nebula VdB 14, in the constellation Camelopardalis.

Alpha Cygni variables are variable stars which exhibit non-radial pulsations, meaning that some portions of the stellar surface are contracting at the same time other parts expand. They are supergiant stars of spectral types B or A. Variations in brightness on the order of 0.1 magnitudes are associated with the pulsations, which often seem irregular, due to beating of multiple pulsation periods. The pulsations typically have periods of several days to several weeks.

<span class="mw-page-title-main">V382 Carinae</span> Star in the constellation Carina

V382 Carinae, also known as x Carinae, is a yellow hypergiant in the constellation Carina. It is a G-type star with a mean apparent magnitude of +3.93, and a variable star of low amplitude.

<span class="mw-page-title-main">Kappa Cassiopeiae</span> Star in the constellation Cassiopeia

Kappa Cassiopeiae is a star in the constellation Cassiopeia.

Omicron<sup>1</sup> Centauri Star in the constellation Centaurus

Omicron1 Centauri is a star in the constellation Centaurus. It is approximately 10,000 light years from Earth.

<span class="mw-page-title-main">Zeta Cephei</span> Star in the constellation Cepheus

Zeta Cephei is a red supergiant star, located about 1000 light-years away in the constellation of Cepheus. Zeta Cephei marks the left shoulder of Cepheus, the King of Ethiopia. It is one of the fundamental stars of the MK spectral sequence, defined as type K1.5 Ib.

<span class="mw-page-title-main">V Aquilae</span> Star in the constellation Aquila

V Aquilae is a carbon star and semiregular variable star in the constellation Aquila. It has an apparent magnitude which varies between 6.6 and 8.4 and is located around 400 parsecs (1,300 ly) away.

<span class="mw-page-title-main">V810 Centauri</span> Star in the constellation Centaurus

V810 Centauri is a double star consisting of a yellow hypergiant primary and blue giant secondary. It is a small amplitude variable star, entirely due to the supergiant primary which is visually over three magnitudes brighter than the secondary. It is the MK spectral standard for class G0 0-Ia.

<span class="mw-page-title-main">TZ Cassiopeiae</span> Star in the constellation Cassiopeia

TZ Cassiopeiae(TZ Cas, HIP 117763, SAO 20912) is a variable star in the constellation Cassiopeia with an apparent magnitude of around +9 to +10. It is approximately 8,400 light-years away from Earth. The star is a red supergiant star with a spectral type of M3 and a temperature around 3,600 K.

<span class="mw-page-title-main">HD 168607</span> Star in the constellation Sagittarius

HD 168607 is a blue hypergiant and luminous blue variable (LBV) star located in the constellation of Sagittarius, easy to see with amateur telescopes. It forms a pair with HD 168625, also a blue hypergiant and possible luminous blue variable, that can be seen at the south-east of M17, the Omega Nebula.

<span class="mw-page-title-main">55 Cygni</span> Star in the constellation Cygnus

55 Cygni is a blue supergiant star in the constellation Cygnus. It is thought to be a member of the Cygnus OB7 stellar association at about 2,700 light years.

<span class="mw-page-title-main">9 Cephei</span> Star in the constellation Cepheus

9 Cephei, also known as V337 Cephei, is a variable star in the constellation Cepheus.

<span class="mw-page-title-main">PZ Cassiopeiae</span> Star in the constellation Cassiopeia

PZ Cassiopeiae is a red supergiant star located in the constellation of Cassiopeia, and a semi-regular variable star.

<span class="mw-page-title-main">13 Monocerotis</span> Star in the constellation Monoceros

13 Monocerotis is a class A0 Ib star in the constellation Monoceros. Its apparent magnitude is 4.5 and it is approximately 780 parsecs (2,500 ly) away.

<span class="mw-page-title-main">Sigma Ophiuchi</span> Star in the constellation Ophiuchus

Sigma Ophiuchi, Latinized from σ Ophiuchi, is a single, orange-hued star in the equatorial constellation Ophiuchus. Its apparent visual magnitude is 4.31, which is bright enough to be faintly visible to the naked eye. The annual parallax shift of 3.62 mas as seen from Earth provides a distance estimate of roughly 900 light years. It is moving closer to the Sun with a radial velocity of −28 km/s.

<span class="mw-page-title-main">9 Persei</span> Blue supergiant star in the constellation Perseus

9 Persei is a single variable star in the northern constellation Perseus, located around 4,300 light years away from the Sun. It has the Bayer designation i Persei; 9 Persei is the Flamsteed designation. This body is visible to the naked eye as a faint, white-hued star with an apparent visual magnitude of about 5.2. It is moving closer to the Sun with a heliocentric radial velocity of −15.2 km/s. The star is a member of the Perseus OB1 association of co-moving stars.

<span class="mw-page-title-main">10 Persei</span> Blue supergiant star in the constellation Perseus

10 Persei is a blue supergiant star in the constellation Perseus. Its apparent magnitude is 6.26 although it is slightly variable.

<span class="mw-page-title-main">3 Geminorum</span> Star in the constellation Gemini

3 Geminorum is a blue supergiant star in the constellation Gemini. It is a small amplitude pulsating variable and a close double star, with a mean combined apparent visual magnitude of about 5.7.

<span class="mw-page-title-main">S Cassiopeiae</span> Star in the constellation Cassiopeia

S Cassiopeiae is a Mira variable and S-type star in the constellation Cassiopeia. It is an unusually cool star, rapidly losing mass and surrounded by dense gas and dust producing masers.

References

  1. 1 2 3 4 5 van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv: 0708.1752 . Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID   18759600. Vizier catalog entry
  2. 1 2 3 Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237: 0. Bibcode:2002yCat.2237....0D.
  3. 1 2 3 Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1: B/gcvs. Bibcode:2009yCat....102025S.
  4. Chentsov, E. L.; Ermakov, S. V.; Klochkova, V. G.; Panchuk, V. E.; Bjorkman, K. S.; Miroshnichenko, A. S. (2003). "An atlas of spectra of B6-A2 hypergiants and supergiants from 4800 to 6700Å". Astronomy and Astrophysics. 397 (3): 1035–1042. Bibcode:2003A&A...397.1035C. doi: 10.1051/0004-6361:20021430 . ISSN   0004-6361.
  5. Mel'Nik, A. M.; Efremov, Yu. N. (1995). "A new list of OB associations in our galaxy". Astronomy Letters. 21 (1): 10. Bibcode:1995AstL...21...10M.
  6. 1 2 3 4 Verdugo, Eva; Talavera, Antonio; Gómez De Castro, Ana I.; Henrichs, Huib F. (2003). "Search for magnetic fields in A-type supergiants". A Massive Star Odyssey: From Main Sequence to Supernova. 212: 255. Bibcode:2003IAUS..212..255V.
  7. Achmad, L.; Lamers, H. J. G. L. M.; Pasquini, L. (1997). "Radiation driven wind models for A, F and G supergiants". Astronomy and Astrophysics. 320: 196. Bibcode:1997A&A...320..196A.
  8. 1 2 3 Prugniel, P.; Vauglin, I.; Koleva, M. (2011). "The atmospheric parameters and spectral interpolator for the MILES stars". Astronomy & Astrophysics. 531: A165. arXiv: 1104.4952 . Bibcode:2011A&A...531A.165P. doi:10.1051/0004-6361/201116769. S2CID   54940439.
  9. Skiff, B. A. (2014). "VizieR Online Data Catalog: Catalogue of Stellar Spectral Classifications (Skiff, 2009- )". VizieR On-line Data Catalog. Bibcode:2014yCat....1.2023S.
  10. 1 2 Koen, Chris; Eyer, Laurent (2002). "New periodic variables from the Hipparcos epoch photometry". Monthly Notices of the Royal Astronomical Society. 331 (1): 45–59. arXiv: astro-ph/0112194 . Bibcode:2002MNRAS.331...45K. doi: 10.1046/j.1365-8711.2002.05150.x . S2CID   10505995.
  11. "Hipparcos Tools Interactive Data Access". Hipparcos. ESA. Retrieved 8 December 2021.
  12. Barsukova, E. A.; Chentsov, E. L. (1990). "The atmosphere of the supergiant 6 Cas. IV. The spectrum and radial velocities of the visual companion". Astrofiz. Issled. Izv. Spets. Astrofiz. Obs. 29: 101. Bibcode:1990AISAO..29..101B.
  13. Bartaya, R. A.; Chargeishvili, K. B.; Chentsov, E. L.; Shkhagosheva, Z. U. (1994). "Hypergiant 6 Cas and association Cas OB5". Bulletin of the Special Astrophysical Observatory. 38: 103. Bibcode:1994BSAO...38..103B.
  14. 1 2 Maíz Apellániz, J.; Barbá, R. H.; Fariña, C.; Sota, A.; Pantaleoni González, M.; Holgado, G.; Negueruela, I.; Simón-Díaz, S. (2021). "Lucky spectroscopy, an equivalent technique to lucky imaging". Astronomy & Astrophysics. 646: A11. arXiv: 2011.12250 . doi: 10.1051/0004-6361/202039479 . S2CID   227151330.