V762 Cassiopeiae

Last updated
V762 Cassiopeiae
V762 Cassiopeiae.png
The location of V762 Cassiopeiae
Observation data
Epoch J2000.0        Equinox J2000.0
Constellation Cassiopeia
Right ascension 01h 16m 11.902s [1]
Declination +71° 44 37.83 [1]
Apparent magnitude  (V)5.82 5.95 [2]
Characteristics
Evolutionary stage Red supergiant [3]
Spectral type K5 I [3] [2]
Variable type Slow irregular variable [2]
Astrometry
Radial velocity (Rv)−21.37±0.91 [1]  km/s
Proper motion (μ)RA: -1.658  mas/yr [1]
Dec.: 1.791  mas/yr [1]
Parallax (π)1.3148 ± 0.0693  mas [1]
Distance 2,500 ± 100  ly
(760 ± 40  pc)
Details
Mass 16.9±2.2 [4]   M
Radius 265.7 [5]   R
Luminosity 14,970 [5]   L
Temperature 3869±145 [3] [5]   K
Age 10.0±1.6 [4]   Myr
Other designations
V762 Cas, BD+70 90, HD  7389, HIP  5926, HR  365, SAO  4358, TYC  4305-2038-1 [6]
Database references
SIMBAD data

V762 Cassiopeiae is a red supergiant and a variable star located about 2,500 light-years away in the Cassiopeia constellation. Its apparent magnitude vary between 5.82 and 5.95, which makes it faintly visible to the naked eye under dark skies. It is a relatively cool star with an average surface temperature of 3,869  K.

Contents

Characteristics

A light curve for V762 Cassiopeiae, plotted from Hipparcos data V762CasLightCurve.png
A light curve for V762 Cassiopeiae, plotted from Hipparcos data

V762 Cassiopeiae has a spectral classification of K0 I, [3] meaning that it is an evolved K-type red supergiant star. It is estimated to be ten million years old, has around 16.9 times the Sun's mass [4] and has expanded to 266 times the Sun's diameter. It radiates 15,000 times the solar luminosity from its photosphere at an effective temperature of 3869  K, [5] which gives it an orange-red hue, typical of red supergiants. [8] Parallax measurements from the Gaia spacecraft show that V762 Cassiopeiae is located 2,480 light-years away. [1] At the estimated distance, V762 Cassiopeiae's apparent brightness is diminished by 1.04 magnitudes due to interstellar extinction. [5]

Hipparcos satellite data showed that the star is variable, and because of that it was given the variable-star designation V762 Cassiopeiae, in 1999. [9] The variability amplitude in visible light is only about 0.1 magnitudes. The International Variable Star Index lists it as an irregular variable, [2] but the General Catalogue of Variable Stars (GCVS) classifies it as a BY Draconis star. [10] The designation of GCVS is likely erroneous, since BY Draconis variability is a characteristic of main sequence stars. [11]

Distance and titleholding

Some websites claim V762 Cassiopeiae is the "farthest star visible to the naked eye", at a distance of 16,308 light-years. [12] [13] This is inconsistent with parallax measurements from both Hipparcos, which found a parallax of 1.18±0.45  mas , corresponding to a distance of about 2,800 light-years, [14] and Gaia DR3, which lists a parallax of 1.3148±0.0693 mas, corresponding to a distance of about 2,500 light-years. [1] [lower-alpha 1] The websites claiming that V762 Cassiopeiae is the "farthest star visible to the naked eye" also do not cite any references for the distance of 16,308 light-years, making the origin of this value uncertain.

Notes

  1. The distance (in parsecs) is equivalent to the inverse of the parallax (in arcseconds).

Related Research Articles

Iota<sup>1</sup> Scorpii Star in the constellation Scorpius

Iota1 Scorpii, Latinized from ι1 Scorpii, is a star in the southern constellation of Scorpius. With an apparent visual magnitude of 3.03, this star can be seen with the naked eye. It is sometimes called by the proper name Apollyon. Parallax measurements place it at a distance of roughly 1,930 light-years from Earth, with a 9% margin of error.

Omicron<sup>1</sup> Canis Majoris Variable star in the constellation Canis Major

Omicron1 Canis Majoris is a red supergiant star in the constellation Canis Major. It is also a variable star.

Psi<sup>1</sup> Aurigae Star in the constellation Auriga

Psi1 Aurigae is a star in the northern constellation of Auriga. It is faintly visible to the naked eye with an apparent visual magnitude of 4.91. Based upon a measured annual parallax shift of 0.44 mas, it is approximately 7,500 light-years distant from the Earth. It is receding from the Sun with a radial velocity of +4.7 km/s.

<span class="mw-page-title-main">V520 Carinae</span> Star in the constellation Carina

V520 Carinae is a single star in the southern constellation of Carina. It has the Bayer designation w Carinae, while V520 Carinae is a variable star designation. The star has an orange hue and is faintly visible to the naked eye with an apparent visual magnitude that fluctuates around +4.58. It is located at a distance of approximately 1,140 light years from the Sun based on parallax, and it is drifting further away with a radial velocity of +9 km/s. It is a candidate member of the IC 2391 moving group of co-moving stars.

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

Kappa Cassiopeiae is a star in the constellation Cassiopeia.

<span class="mw-page-title-main">4 Cassiopeiae</span> Star in the constellation Cassiopeia

4 Cassiopeiae is a red giant in the northern constellation of Cassiopeia, located approximately 790 light-years away from the Sun. It is visible to the naked eye as a faint, red-hued star with a baseline apparent visual magnitude of 4.96. At the distance of this system, its visual magnitude is diminished by an extinction of 0.56 due to interstellar dust. This system is moving closer to the Earth with a heliocentric radial velocity of −39 km/s.

<span class="mw-page-title-main">6 Cassiopeiae</span> Star in the constellation Cassiopeia

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

<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">HD 44131</span> Star in the constellation Orion

HD 44131 is a star in the equatorial constellation of Orion, positioned near the eastern constellation border with Monoceros. It has a reddish hue and is faintly visible to the naked eye with an apparent visual magnitude of 4.91. The star is located at a distance of approximately 465 light years from the Sun based on parallax, and it is drifting further away with a radial velocity of +48.6 km/s. Based on radial velocity variations, it is a candidate spectroscopic binary system and a preliminary orbital solution was published in 1991 with a period of 9.29 yr. However, these velocity variations may be due to other causes.

<span class="mw-page-title-main">Chi Pegasi</span> Red giant star in the constellation Pegasus

Chi Pegasi, Latinised from χ Pegasi, is a single star in the northern constellation of Pegasus, along the eastern constellation border with Pisces. It has a reddish hue and is faintly visible to the naked eye with an apparent visual magnitude of 4.80. The distance to this star is approximately 368 light-years based on parallax, but it is drifting closer with a radial velocity of −46 km/s.

<span class="mw-page-title-main">V1073 Scorpii</span> Variable star in the constellation Scorpius

V1073 Scorpii is a variable star in the constellation Scorpius. It has a non-Greek Bayer designation of k Scorpii. The star has a blue-white hue and is visible to the naked eye with an apparent visual magnitude that fluctuates around +4.87. Parallax measurements yield a distance estimate of approximately 2,920 ly (896 pc) from the Sun, and it is drifting further away with a radial velocity of +7 km/s. It has an absolute magnitude of −6.8

<span class="mw-page-title-main">GX Velorum</span> Star in the constellation Vela

GX Velorum is a solitary variable star in the southern constellation of Vela. It is visible to the naked eye as a faint, blue-white hued star with an apparent visual magnitude that fluctuates around 4.99. Based upon parallax measurements, it is located approximately 4,200 light years distant from the Sun, and is drifting further away with a radial velocity of +28 km/s. It may be a member of the Vela OB1 association of co-moving stars.

<span class="mw-page-title-main">V4024 Sagittarii</span> Star in the constellation Sagittarius

V4024 Sagittarii is a single variable star in the southern constellation of Sagittarius. It has a blue-white hue and is dimly visible to the naked eye with an apparent visual magnitude that fluctuates from about 5.3 to 5.6. The star is located at a distance of approximately 1,700 light years based on stellar parallax, but is drifting closer with a radial velocity of −20 km/s. The position of this star near the ecliptic means it is subject to lunar occultations.

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

BO Carinae, also known as HD 93420, is an irregular variable star in the constellation Carina.

<span class="mw-page-title-main">HD 77887</span> Star in the constellation Volans

HD 77887 is a solitary star located in the southern circumpolar constellation Volans. It has an apparent magnitude of 5.87, making it faintly visible to the naked eye if viewed under ideal conditions. The star is situated at a distance of about 760 light years but is receding with a heliocentric radial velocity of 12.6 km/s.

HD 1032 is a solitary star in the southern circumpolar constellation Octans. It is faintly visible to the naked eye with an apparent magnitude of 5.77 and is estimated to be 850 light years away from the Solar System based on parallax measure. However, it is receding with a heliocentric radial velocity of 4 km/s.

<span class="mw-page-title-main">SY Equulei</span> High galactic latitude β Cephei variable

SY Equulei, also known as HD 203664, is a single variable star located in the equatorial constellation Equuleus. It has an average apparent magnitude of about 8.5, varying by a few hundredths of a magnitude, making it readily visible in binoculars and small telescopes, but not to the naked eye. The star is relatively far away at a distance of 8,000 light years and is receding with a heliocentric radial velocity of 48 km/s. At that distance, SY Equulei is dimmed by 0.19 magnitudes due to interstellar dust.

<span class="mw-page-title-main">HD 44506</span> Star in the constellation of Columba

HD 44506 is a solitary, blue hued star located in the southern constellation Columba. The object is also called HR 2288, which is its Bright Star Catalog designation. It has an average apparent magnitude of 5.52, making it faintly visible to the naked eye under ideal conditions. HD 44506 is located relatively far at a distance of 1,800 light years based on Gaia DR3 parallax measurements but is receding with a heliocentric radial velocity of 54 km/s.

<span class="mw-page-title-main">HD 187086</span> Astrometric binary and suspected variable star

HD 187086, also known as HR 7537, is a probable astrometric binary located in the southern constellation Telescopium. It has an average apparent magnitude of 5.9, making it faintly visible to the naked eye. The star is located relatively far at a distance of 1,020 light years based on Gaia DR3 parallax measurements but is rapidly drifting closer with a heliocentric radial velocity of −64 km/s. At its current distance, HD 187086's brightness is diminished by 0.27 magnitudes due to interstellar dust. It has an absolute magnitude of −0.8.

<span class="mw-page-title-main">V718 Coronae Australis</span> Slow irregular variable; Corona Australis

V718 Coronae Australis is a solitary variable star located in the southern constellation Corona Australis. It is faintly visible to the naked eye as a red-hued point of light with an apparent magnitude of 5.43. Gaia DR3 parallax measurements imply a distance of 630 light years and it is currently receding with a heliocentric radial velocity of 28.5 km/s. At its current distance V718 CrA's brightness is diminished by 0.37 magnitudes due to interstellar dust and it has an absolute magnitude of −1.03.

References

  1. 1 2 3 4 5 6 7 8 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv: 2208.00211 . Bibcode:2023A&A...674A...1G. doi: 10.1051/0004-6361/202243940 . S2CID   244398875. Gaia DR3 record for this source at VizieR.
  2. 1 2 3 4 "V0762 Cas". The International Variable Star Index. AAVSO. Retrieved 8 May 2024.
  3. 1 2 3 4 Messineo, M.; Brown, A. G. A. (2019-07-01). "A Catalog of Known Galactic K-M Stars of Class I Candidate Red Supergiants in Gaia DR2". The Astronomical Journal. 158 (1): 20. arXiv: 1905.03744 . Bibcode:2019AJ....158...20M. doi: 10.3847/1538-3881/ab1cbd . ISSN   0004-6256. Data can be acessed here at VizieR.
  4. 1 2 3 Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (2011-01-01). "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun". Monthly Notices of the Royal Astronomical Society. 410 (1): 190–200. arXiv: 1007.4883 . Bibcode:2011MNRAS.410..190T. doi:10.1111/j.1365-2966.2010.17434.x. ISSN   0035-8711. Data can be acessed here at VizieR.
  5. 1 2 3 4 5 Healy, Sarah; Horiuchi, Shunsaku; Molla, Marta Colomer; Milisavljevic, Dan; Tseng, Jeff; Bergin, Faith; Weil, Kathryn; Tanaka, Masaomi (2024-03-23). "Red Supergiant Candidates for Multimessenger Monitoring of the Next Galactic Supernova". Monthly Notices of the Royal Astronomical Society. 529 (4): 3630–3650. doi:10.1093/mnras/stae738. ISSN   0035-8711.
  6. "HD 7389". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 9 April 2024.
  7. EAS (1997). "The HIPPARCOS and TYCHO catalogues". Astrometric and Photometric Star Catalogues Derived from the ESA Hipparcos Space Astrometry Mission. ESA SP Series. 1200. Noordwijk, Netherlands: ESA Publications Division. Bibcode:1997ESASP1200.....E. ISBN   9290923997 . Retrieved 15 October 2022.
  8. "The Colour of Stars". Australia National Telescope Facility. Retrieved 2024-05-27.
  9. Kazarovets, E. V.; Samus, N. N.; Durlevich, O. V.; Frolov, M. S.; Antipin, S. V.; Kireeva, N. N.; Pastukhova, E. N. (January 1999). "The 74th Special Name-list of Variable Stars" (PDF). Information Bulletin on Variable Stars. 4659: 1. Bibcode:1999IBVS.4659....1K . Retrieved 8 May 2024.
  10. "Query= V762 Cas". General Catalogue of Variable Stars. Lomonosov Moscow State University. Retrieved 8 May 2024.
  11. Chahal, Deepak; de Grijs, Richard; Kamath, Devika; Chen, Xiaodian (2022-07-06). "Statistics of BY Draconis Chromospheric Variable Stars". Monthly Notices of the Royal Astronomical Society. 514 (4): 4932–4943. arXiv: 2206.05505 . doi:10.1093/mnras/stac1660. ISSN   0035-8711.
  12. "Farthest Star You Can See With The Unaided Eye". Cosmoknowledge. 2021-03-26. Retrieved 2024-04-11.
  13. "How Far Back In Time Can We See With Our Naked Eye?". Big Think. 2021-05-17. Retrieved 2024-04-11.
  14. "HIP 5926". VizieR . Centre de données astronomiques de Strasbourg. Retrieved 11 April 2024.