CW Octantis

Last updated
CW Octantis
CWOctLightCurve.png
A light curve for CW Octantis, plotted from TESS data [1]
Observation data
Epoch J2000.0        Equinox J2000.0 (ICRS)
Constellation Octans
Right ascension 17h 00m 58.51777s [2]
Declination −86° 21 51.4707 [2]
Apparent magnitude  (V)6.03±0.01 [3]
Characteristics
Evolutionary stage subgiant [4]
Spectral type A3 IV [5]
U−B color index +0.02 [6]
B−V color index +0.05 [6]
Variable type α2 CVn [7]
Astrometry
Radial velocity (Rv)7.1±0.5 [8]  km/s
Proper motion (μ)RA: +8.413  mas/yr [2]
Dec.: −0.032  mas/yr [2]
Parallax (π)5.1828 ± 0.0486  mas [2]
Distance 629 ± 6  ly
(193 ± 2  pc)
Absolute magnitude  (MV)−0.36 [9]
Details
Mass 2.98±0.05 [4]   M
Radius 4.64 [10]   R
Luminosity 111 [11]   L
Surface gravity (log g)3.45±0.07 [12]   cgs
Temperature 8,791 [13]   K
Metallicity [Fe/H]+0.6 [14]   dex
Rotation ≈2.8 days [13]
Rotational velocity (v sin i)92±6 [13]  km/s
Age 188±4 [4]   Myr
Other designations
26 G. Octantis [15] , CW Octantis, CD−86°100, CPD−86°333, FK5  921, GC  22519, HD  148542, HIP  83255, HR  6139, SAO  258751 [16]
Database references
SIMBAD data

CW Octantis, also known as HD 148542, is a solitary, white hued variable star located in the southern circumpolar constellation Octans. It has an apparent magnitude of 6.03, allowing it to be faintly visible to the naked eye. Parallax measurements from Gaia DR3 place the object at a distance of 629 light years. It appears to be receding from the Solar System with a heliocentric radial velocity of 7.1  km/s .

CW Octantis has a stellar classification of A3 IV, indicating that it is an evolved A-type star heading towards the red giant branch. Zorec and Royer (2012) model it as a dwarf star that has just reached the end of its main sequence lifetime. [4] It has 2.98 times the mass of the Sun [4] and 4.6 times its radius. [10] It radiates 111 times the luminosity of the Sun [11] from its photosphere at an effective temperature of 8,791  K . [13] CW Octantis is estimated to be 188 million years old. [4]

This object is classified as a Alpha2 Canum Venaticorum variable. [7] Most stars of this class have chemical peculiarities in their spectra, but CW Octantis seems to be ordinary. Renson and Manfroid (2009) consider its pecuilarity status to be doubtful. [17] Nevertheless, CW Octantis fluctuates between 6.05 and 6.07 in the Hipparcos passband within 2.63 days. [18] It takes 2.8 days to complete a full a rotation, which corresponds to a projected rotational velocity of 92  km/s . [13]

Related Research Articles

<span class="mw-page-title-main">HD 24479</span> Star in the constellation Camelopardalis

HD 24479, also designated as HR 1204, is a solitary, bluish-white hued star located in the northern circumpolar constellation Camelopardalis. The star is visible to the naked eye with an apparent visual magnitude of 5.04. Based on Gaia DR3 parallax measurements, it is located 385 light years from the Sun. However, it is receding with a somewhat constrained heliocentric radial velocity of 4.6 km/s. At its current distance, HD 24479's brightness is diminished by 0.29 magnitudes due to interstellar dust.

HD 96146 is a binary star located in the southern constellation Antlia. The system has a combined apparent magnitude of 5.41, making it visible to the naked eye under ideal conditions. Parallax measurements from the Gaia spacecraft place the pair at a distance of 710 light years with a large margin of error. It is currently receding with a poorly constrained heliocentric radial velocity of 4.7 km/s.

HD 86267, also known as HR 3932, is a solitary orange-hued star located in the southern constellation Antlia. It has an apparent magnitude of 5.82, allowing it to be faintly seen with the naked eye. Parallax measurements place it a distance of 514 light years and it is currently receding with a heliocentric radial velocity of 3.7 km/s.

HD 126209, also known as HR 5389, is a solitary, orange hued star located in the southern circumpolar constellation Apus. It has an apparent magnitude of 6.06, making it faintly visible to the naked eye under ideal conditions. Based on parallax measurements from the Gaia spacecraft, the object is estimated to be 560 light years distant. It appears to be approaching the Solar System with a fairly constrained heliocentric radial velocity of −8.1 km/s. De Mederios et al. (2014) found the radial velocity to be variable, making it a probable spectroscopic binary. Eggen (1993) lists it as a member of the old disk population.

HD 30080, also known as HR 1509, is a solitary, orange hued star located in the southern constellation Caelum, the chisel. It has an apparent magnitude of 5.66, allowing it to be faintly visible to the naked eye. Parallax measurements from Gaia DR3 place the object at a distance of 612 light years. It appears to be approaching the Solar System with a heliocentric radial velocity of −3.8 km/s. Eggen (1989) lists it as a member of the thick disk population.

<span class="mw-page-title-main">HD 26764</span> Star in the constellation Camelopardalis

HD 26764, also known as HR 1314 or rarely 14 H. Camelopardalis, is a solitary white hued star located in the northern circumpolar constellation Camelopardalis. It has an apparent magnitude of 5.19, making it faintly to the naked eye if viewed under good conditions. Gaia DR3 parallax measurements place the object at a distance of 266 light years and is drifting closer with a poorly constrained heliocentric radial velocity of 3 km/s. At its current distance, HD 26764's brightness is diminished by 0.26 magnitudes due to interstellar dust.

HD 75116, also known as HR 3491, is a solitary, orange hued star in the southern circumpolar constellation Volans, the flying fish. It has an apparent magnitude of 6.31, placing it near the limit for naked eye visibility. Parallax measurements from the Gaia spacecraft place the star relatively far at a distance of 930 light years. It appears to be approaching the Solar System, having a heliocentric radial velocity of −17.5 km/s.

<span class="mw-page-title-main">Eta Octantis</span> Star in the constellation of Octans

Eta Octantis, Latinized from η Octantis, is a solitary star located in the southern circumpolar constellation Octans. It has an apparent magnitude of 6.19, making it faintly visible to the naked eye. The object is situated at a distance of 358 light years but is approaching the Solar System with a heliocentric radial velocity of −1.7 km/s.

<span class="mw-page-title-main">Tau Octantis</span> Star in the southern constellation of Octans

Tau Octantis, Latinized from τ Octantis, is a solitary star in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.50, allowing it to be faintly seen with the naked eye. The object is located at a distance of 480 light years but is receding with a heliocentric radial velocity of 31 km/s.

<span class="mw-page-title-main">Xi Octantis</span> Slowly pulsating B dwarf in Octans

Xi Octantis, Latinized from ξ Octantis, is a solitary variable star in the southern circumpolar constellation Octans. It has an apparent magnitude of about 5.3, allowing it to be faintly seen with the naked eye; however, this varies slightly. Located 514 light years away, the object is receding with a heliocentric radial velocity of 22 km/s.

HD 75171, also known as HR 3495, is a solitary, white hued star located in the southern constellation of Volans. It has an apparent magnitude of 6.02, making it faintly visible to the naked eye under ideal conditions. The object is relatively close at a distance of 191 light years but is receding with a heliocentric radial velocity of 10.7 km/s. Eggen (1995) lists it as a probable member of the Hyades Supercluster.

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

WZ Columbae, also known as HD 38170, is a solitary, bluish-white hued star located in the southern constellation Columba, the dove. It has an apparent magnitude of 5.28, allowing it to be faintly visible to the naked eye. Based on parallax measurements from the Gaia spacecraft, the object is about 365 light years distant. It appears to be receding from the Solar System, having a heliocentric radial velocity of 36.3 km/s.

HD 31529, also known as HR 1584, is a solitary, orange hued star located in the southern constellation Caelum, the chisel. It has an apparent magnitude of 6.09, making it faintly visible to the naked eye if viewed under ideal conditions. This object is located relatively far at a distance of 932 light years based on parallax measurements from Gaia DR3, but is receding with a heliocentric radial velocity of 28.4 km/s. Eggen (1989) lists it as a member of the old disk population.

HD 26670, also known as HR 1305, is a star located in the northern circumpolar constellation of Camelopardalis, the giraffe. The object has been designated as 26 H. Camelopardalis, but is not commonly used in modern times. It has an apparent magnitude of 5.70, allowing it to be faintly visible to the naked eye. Based on parallax measurements from Gaia DR3, the object is estimated to be 491 light years away from the Solar System. It appears to be slowly receding with a heliocentric radial velocity of 0.4 km/s.

<span class="mw-page-title-main">23 Leonis Minoris</span> Star in the constellation of Leo Minor

23 Leonis Minoris is a solitary, bluish-white hued star located in the northern constellation Leo Minor. It is positioned 7° south and 11" west from β Leonis Minoris. It is rarely called 7 H. Leonis Minoris, which is its Hevelius designation.

<span class="mw-page-title-main">40 Leonis Minoris</span> Binary star system in the constellation of Leo Minor

40 Leonis Minoris is a white hued star located in the northern constellation Leo Minor. It is rarely called 14 H. Leonis Minoris, which is the designation given by Polis astronomer Johann Hevelius.

<span class="mw-page-title-main">HD 198716</span> Star in the constellation of Microscopium

HD 198716, also known as HR 7987 or 33 G. Microscopii, is a solitary star located in the southern constellation Microscopium. Eggen (1993) lists it as a member of the Milky Way's old disk population.

<span class="mw-page-title-main">HD 118285</span> SPB star in the constellation Chamaeleon.

HD 118285, also known as HR 5115, is a variable star located in the southern circumpolar constellation Chamaeleon. DY Chamaeleontis is its variable star designation. It has an average apparent magnitude of 6.32, placing it near the limit for naked eye visibility. The object is located relatively far at a distance of 864 light years based on Gaia DR3 parallax measurements but is receding with a heliocentric radial velocity of 18 km/s. At its current distance, HD 118285's brightness is diminished by 0.58 magnitudes due to interstellar dust.

<span class="mw-page-title-main">HD 168592</span> Star in the constellation of Corona Australis

HD 168592, also designated as HR 6862 or rarely 7 G. Coronae Australis, is a solitary star located in the southern constellation Corona Australis. It is faintly visible to the naked eye as an orange-hued star with an apparent magnitude of 5.07. Gaia DR3 parallax measurements place it at a distance of 490 light years and is currently receding with a heliocentric radial velocity of 18 km/s. At its current distance, HD 168592's brightness is diminished by 0.38 magnitudes due to interstellar dust. It has an absolute magnitude of −0.76.

<span class="mw-page-title-main">HD 31134</span> A-type dwarf; Camelopardalis

HD 31134, also designated as HR 1561, is a solitary star located in the northern circumpolar constellation Camelopardalis, the giraffe. It is faintly visible to the naked eye as a white-hued star with an apparent magnitude of 5.74. Gaia DR3 parallax measurements place it 473 light years away. It appears to be approaching the Solar System with a heliocentric radial velocity of −15.1 km/s. At its current distance, HD 31134's brightness is diminished by 0.35 magnitudes due to interstellar dust. It has an absolute magnitude of +0.19.

References

  1. "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 1 October 2022.
  2. 1 2 3 4 5 Vallenari, A.; et al. (Gaia Collaboration) (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics . arXiv: 2208.00211 . doi: 10.1051/0004-6361/202243940 . Gaia DR3 record for this source at VizieR.
  3. Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. ISSN   0004-6361.
  4. 1 2 3 4 5 6 Zorec, J.; Royer, F. (January 2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". Astronomy and Astrophysics. 537: A120. arXiv: 1201.2052 . Bibcode:2012A&A...537A.120Z. doi: 10.1051/0004-6361/201117691 . ISSN   0004-6361. S2CID   55586789.
  5. de Vaucouleurs, A. (1 August 1957). "Spectral Types and Luminosities of B, A and F Southern Stars". Monthly Notices of the Royal Astronomical Society. 117 (4): 449–462. Bibcode:1957MNRAS.117..449D. doi: 10.1093/mnras/117.4.449 . eISSN   1365-2966. ISSN   0035-8711.
  6. 1 2 Johnson, H. L.; Mitchell, R. I.; Iriarte, B.; Wisniewski, W. Z. (1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory. 4: 99–110. Bibcode:1966CoLPL...4...99J.
  7. 1 2 Samus’, N. N.; Goranskii, V. P.; Durlevich, O. V.; Zharova, A. V.; Kazarovets, E. V.; Kireeva, N. N.; Pastukhova, E. N.; Williams, D. B.; Hazen, M. L. (July 2003). "An electronic version of the second volume of the General Catalogue of Variable Stars with improved coordinates". Astronomy Letters. 29 (7): 468–479. Bibcode:2003AstL...29..468S. doi:10.1134/1.1589864. eISSN   1562-6873. ISSN   1063-7737. S2CID   16299532.
  8. Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35,495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv: 1606.08053 . Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. eISSN   1562-6873. ISSN   1063-7737. S2CID   119231169.
  9. Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv: 1108.4971 . Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. eISSN   1562-6873. ISSN   1063-7737. S2CID   119257644.
  10. 1 2 Kervella, Pierre; Arenou, Frédéric; Thévenin, Frédéric (2022). "Stellar and substellar companions from Gaia EDR3". Astronomy & Astrophysics. 657: A7. arXiv: 2109.10912 . Bibcode:2022A&A...657A...7K. doi: 10.1051/0004-6361/202142146 . eISSN   1432-0746. ISSN   0004-6361.
  11. 1 2 McDonald, I.; Zijlstra, A. A.; Boyer, M. L. (21 November 2012). "Fundamental parameters and infrared excesses of Hipparcos stars: Parameters and IR excesses from Hipparcos". Monthly Notices of the Royal Astronomical Society. 427 (1): 343–357. arXiv: 1208.2037 . Bibcode:2012MNRAS.427..343M. doi: 10.1111/j.1365-2966.2012.21873.x . ISSN   0035-8711.
  12. Stassun, Keivan G.; et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv: 1905.10694 . Bibcode:2019AJ....158..138S. doi: 10.3847/1538-3881/ab3467 . eISSN   1538-3881.
  13. 1 2 3 4 5 Reiners, A.; Royer, F. (February 2004). "First signatures of strong differential rotation in A-type stars". Astronomy & Astrophysics. 415 (1): 325–329. arXiv: astro-ph/0311341 . Bibcode:2004A&A...415..325R. doi: 10.1051/0004-6361:20034175 . eISSN   1432-0746. ISSN   0004-6361.
  14. Rainer, M.; Poretti, E.; Mistò, A.; Panzera, M. R.; Molinaro, M.; Cepparo, F.; Roth, M.; Michel, E.; Monteiro, M. J. P. F. G. (5 December 2016). "The SpaceInn-SISMA Database: Characterization of a Large Sample of Variable and Active Stars by Means of Harps Spectra". The Astronomical Journal. 152 (6): 207. arXiv: 1611.02715 . Bibcode:2016AJ....152..207R. doi: 10.3847/0004-6256/152/6/207 . eISSN   1538-3881.
  15. Gould, Benjamin Apthorp (1878). "Uranometria Argentina : brillantez y posicion de las estrellas fijas, hasta la septima magnitud, comprendidas dentro de cien grados del polo austral : con atlas". Resultados del Observatorio Nacional Argentino. 1. Bibcode:1879RNAO....1.....G.
  16. "CW Oct". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved October 1, 2022.
  17. Renson, P.; Manfroid, J. (19 March 2009). "Catalogue of Ap, HgMn and Am stars". Astronomy & Astrophysics. 498 (3): 961–966. Bibcode:2009A&A...498..961R. doi: 10.1051/0004-6361/200810788 . eISSN   1432-0746. ISSN   0004-6361.
  18. Watson, C. L.; Henden, A. A.; Price, A. (May 2006). "The International Variable Star Index (VSX)". Society for Astronomical Sciences Annual Symposium. 25: 47. Bibcode:2006SASS...25...47W.