25 Sextantis

Last updated
25 Sextantis
Sextans constellation map.svg
Red circle.svg
Location of 25 Sex on the map (circled)
Observation data
Epoch J2000.0        Equinox J2000.0 (ICRS)
Constellation Sextans
Right ascension 10h 23m 26.47823s [1]
Declination −04° 04′ 26.5182″ [1]
Apparent magnitude  (V)5.97 [2] (5.94 - 5.98) [3]
Characteristics
Evolutionary stage main sequence star [4]
Spectral type B9p Si(CrSr) [5]
U−B color index −0.17 [2]
B−V color index −0.10 [2]
Variable type α2 CVn [3]
Astrometry
Radial velocity (Rv)23.0±3.4 [6]  km/s
Proper motion (μ)RA: −50.818  mas/yr [1]
Dec.: +4.114  mas/yr [1]
Parallax (π)9.4414 ± 0.0598  mas [1]
Distance 345 ± 2  ly
(105.9 ± 0.7  pc)
Absolute magnitude  (MV)+0.86 [7]
Details
Mass 2.48±0.07 [4]   M☉
Radius 2.22±0.11 [8]   R☉
Luminosity 45.7+13.2
−10.2 [9]   L☉
Surface gravity (log g)4.14 [10]   cgs
Temperature 11,500 [11]   K
Metallicity [Fe/H]−0.19 [10]   dex
Rotational velocity (v sin i)24±3 [9]  km/s
Age 309+54
−80 [4]   Myr
Other designations
25 Sex, 43 G. Sextantis [12] , SS Sextantis, BD−03°2911, FK5  388, GC  14268, HD  90044, HIP  50885, HR  4082, SAO  137533, TIC  1712781 [13]
Database references
SIMBAD data

25 Sextantis (HD 90044; HR 4082; 43 G. Sextantis), or simply 25 Sex, is a star located in the equatorial constellation Sextans; it also bears the variable star designation SS Sextantis (SS Sex). With an average apparent magnitude of 5.97, [2] 25 Sex is barely visible to the naked eye, even under ideal conditions. Gaia DR3 parallax measurements imply a distance of 345 light-years, [1] and it is currently drifting away with a heliocentric radial velocity of approximately 23  km/s . [6] At its current distance, 25 Sex's average brightness is diminished by an interstellar extinction of 0.17 magnitudes and it has an absolute magnitude of +0.86. [7]

A light curve for SS Sextantis, plotted from TESS data. The 4.37 day rotation period is shown in red. SSSexLightCurve.png
A light curve for SS Sextantis, plotted from TESS data. The 4.37 day rotation period is shown in red.

The star was first discovered to be variable in 1980 by French astronomers P. Renson & J. Manfroid. They observed a 4.37 day period for 25 Sex and a flucation of 0.03 magnitudes in optical light. [15] The next year, it was confirmed to be variable and it was given the variable star designation SS Sextantis. [16] J. Manfroid and G. Mathys refined the period of 25 Sextantis to be slightly longer than previously measured; the period of SS Sextantis was measured at 4.39 days but with a larger uncertainty. [17] In 1993, D. A. Bohlender and colleagues measured the magnetic field of the star and found that it varied between 650 and 1,200 gauss, although with some uncertainty about the variation. [18] Subsequent observations provide a much wider range between 1 and -1,000 gauss. [19]

25 Sex has a stellar classification of B9pSi(CrSr), [5] indicating that it is a Bp star with abundance of silicon, chromium, and strontium in its spectrum. It has 2.48 times the mass of the Sun [4] and 2.22 times the radius of the Sun. [8] It radiates 45.7 times the luminosity of the Sun [9] from its photosphere at an effective temperature of roughly 11,500  K , [11] giving it a bluish-white hue when viewed in the night sky. 25 Sex is metal deficient with an iron abundance 64.6% of the Sun's [10] and it is estimated to be 309 million years old. [4] At that age, it has completed 56% of its main sequence lifetime. [4] Like many chemically peculiar stars it spins modestly—having a projected rotational velocity of 24  km/s . [9]

Related Research Articles

<span class="mw-page-title-main">63 Andromedae</span> Star in the constellation Andromeda

63 Andromedae is an Alpha2 Canum Venaticorum variable star in the constellation Andromeda. Its variable star designation is PZ Andromedae. With an apparent magnitude of about 5.6, it is bright enough to be seen by naked eye. Based upon an annual parallax shift of 8.53 mas, it is located 382 light years away.

<span class="mw-page-title-main">21 Aquilae</span> Star in the constellation Aquila

21 Aquilae is a solitary variable star in the equatorial constellation of Aquila. It has the variable star designation V1288 Aql; 21 Aquilae is its Flamsteed designation. This object is visible to the naked eye as a dim, blue-white hued star with a baseline apparent visual magnitude of about 5.1. The star is located at a distance of around 680 light-years from Earth, give or take a 20 light-year margin of error. It is moving closer to the Earth with a heliocentric radial velocity of –5 km/s.

<span class="mw-page-title-main">49 Cancri</span> Star in the constellation Cancer

49 Cancri is a single star in the zodiac constellation of Cancer, located 501 light years away from the Sun. It has the Bayer designation b Cancri; 49 Cancri is the Flamsteed designation. It is visible to the naked eye as a faint star with an apparent visual magnitude of about 5.6. It is moving away from the Earth with a heliocentric radial velocity of +27.5 km/s.

<span class="mw-page-title-main">NO Apodis</span> Star in the constellation Apus

NO Apodis is a solitary, red hued variable star located in the southern circumpolar constellation Apus. It has an average apparent magnitude of 5.86, allowing it to be faintly seen with the naked eye. The object is relatively far at a distance of 790 light years but is drifting closer with a heliocentric radial velocity −18.3 km/s.

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

BN Camelopardalis is a suspected astrometric binary in the northern circumpolar constellation of Camelopardalis. It appears as a variable star that is visible to the naked eye as a dim, white-hued point of light with an apparent visual magnitude that fluctuates around 5.49. The system is located at a distance of around 310 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +9 km/s.

Eta<sup>2</sup> Coronae Australis Star in the constellation Corona Austrlis

Eta2 Coronae Australis, Latinized from η2 Coronae Australis, is a solitary star located in the southern constellation of Corona Australis. It is visible to the naked eye as a dim, blue-white hued star with an apparent visual magnitude of 5.59. Gaia DR3 parallax measurements imply a distance of 770 light years from the Solar System, but it is drifting closer with a radial velocity of −23 km/s. At its current distance Eta2 CrA's brightness is diminished by 0.27 magnitudes due to stellar extinction from interstellar dust and it has an absolute magnitude of −0.24.

HD 129899, is a solitary star located in the southern circumpolar constellation Apus, the bird-of-paradise. It has an apparent magnitude of 6.44, placing it near the limit for naked eye visibility, even under ideal conditions. The object is located relatively far at a distance of 928 light-years based on Gaia DR3 parallax measurements and it is receding with a heliocentric radial velocity of 2.5 km/s. At its current distance, HD 129899's brightness is heavily diminished by an interstellar extinction of 0.55 magnitudes and it has an absolute bolometric magnitude of −1.28.

QV Andromedae is an Alpha2 Canum Venaticorum variable in the constellation Andromeda. Its maximum apparent visual magnitude is 6.6, so it can be seen by the naked eye under very favourable conditions. The brightness varies slightly following a periodic cycle of approximately 5.23 days.

<span class="mw-page-title-main">Iota Mensae</span> Star in the constellation Mensa

Iota Mensae is a single star about 880 light years away in the faint constellation Mensa. It has a very slightly variable apparent magnitude of 6.0, making it visible with the naked eye under good skies.

HD 76270, also known as HR 3544, is a solitary, white hued star located in the southern circumpolar constellation Volans. It has an apparent magnitude of 6.10, making it faintly visible to the naked eye if viewed under ideal conditions. The object is relatively far with a distance of 2,360 light years, but is slowly approaching the Solar System with a heliocentric radial velocity of −2.6 km/s.

<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.

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

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.

<span class="mw-page-title-main">PW Telescopii</span> Α2 CVn variable; Telescopium

PW Telescopii, also known as HD 183806 or simply PW Tel, is a solitary variable star located in the southern constellation Telescopium. It has an average apparent magnitude of 5.58, making it faintly visible to the naked eye. Based on parallax measurements from the Gaia satellite, the star is estimated to be 395 light years distant. It appears to be approaching the Solar System with a heliocentric radial velocity of −10 km/s. The value is somewhat constrained, having an uncertainty of 26%. At its current distance, PW Tel's brightness is diminished by 0.05 magnitudes due to interstellar dust.

<span class="mw-page-title-main">HD 31134</span> Star in the constellation of 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.

<span class="mw-page-title-main">V686 Coronae Australis</span> Alpha2 CVn variable; Corona Australis

V686 Coronae Australis is a solitary, bluish-white-hued variable star located in the southern constellation Corona Australis. It has an apparent magnitude that ranges between 5.25 and 5.41, which makes it faintly visible to the naked eye. Gaia DR3 parallax measurements imply a distance of 480 light years and it is slowly receding with a heliocentric radial velocity of 1.3 km/s. At its current distance V686 CrA's average brightness is diminished by 0.35 magnitudes due to extinction from interstellar dust and it has an absolute visual magnitude of −0.24.

<span class="mw-page-title-main">QQ Telescopii</span> Delta Scuti variable; Telescopium

QQ Telescopii, also known as HD 185139 or simply QQ Tel, is a solitary variable star located in the southern constellation Telescopium. It has an apparent magnitude of 6.25, placing it near the limit for naked eye visibility, even under ideal conditions. Gaia DR3 parallax measurements imply a distance of 333 light years and it is currently receding with a heliocentric radial velocity of 7.8 km/s. At its current distance, QQ Telescopii's brightness is diminished by two tenths of a magnitude due to interstellar dust and it has an absolute magnitude of +1.01.

<span class="mw-page-title-main">V692 Coronae Australis</span> SX Areits variable; Corona Australis

V692 Coronae Australis, or simply V692 CrA, is a whitish-blue hued variable star located in the southern constellation Corona Australis. It has a maximum apparent magnitude of 5.46, making it faintly visible to the naked eye. The object is located relatively far at a distance of approximately 1,900 light years based on Gaia DR3 parallax measurements, but it is approaching the Solar System with a fairly constrained heliocentric radial velocity of −15.3 km/s. At its current distance, V692 CrA's brightness is heavily diminished by 0.46 magnitudes due to extinction due to interstellar dust. Its absolute magnitude depends on the source: Westin (1985) gave a value of −6.44 while the extended Hipparcos catalogue gave a value of −2.26.

<span class="mw-page-title-main">V701 Coronae Australis</span> Delta Scuti variable; Corona Australis

V701 Coronae Australis, or simply V701 CrA, is a solitary, yellowish-white hued variable star located in the southern constellation Corona Australis. It has an average apparent magnitude of 5.72, making it faintly visible to the naked eye under ideal conditions. The object is located relatively close at a distance of 213 light-years based on Gaia DR3 parallax measurements, and it is currently receding with a poorly constrained heliocentric radial velocity of 4 km/s. At its current distance, V701 CrA's brightness is diminished by a quarter of a magnitude due to extinction and it has an absolute magnitude of +1.55.

<span class="mw-page-title-main">18 Sextantis</span> K-type giant star in the constellation Sextans

18 Sextantis, or simply 18 Sex, is a solitary star located in the southern constellation Sextans. It is faintly visible to the naked eye as an orange-hued point of light with an apparent magnitude of 5.62. Gaia DR3 parallax measurements imply a distance of 558 light-years and it is slowly receding with a poorly constrained heliocentric radial velocity of approximately 0.2 km/s. At its current distance, 18 Sex's brightness is diminished with an interstellar extinction of two-tenths of a magnitude and it has an absolute magnitude of −0.16.

<span class="mw-page-title-main">35 Sextantis</span> Triple star system in Sextans

35 Sextantis, or simply 35 Sex, is a triple star system located in the equatorial constellation Sextans. The primary has an apparent magnitude of 6.09, making it barely visible to the naked eye, even under ideal conditions. The companion has an apparent magnitude of 7.01, making it readily visible in binoculars, but not to the naked eye. The system is located relatively far at a distance of approximately 700 light-years but it is drifting closer with a combined heliocentric radial velocity of −2.18 km/s.

References

  1. 1 2 3 4 5 6 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 Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". VizieR Online Data Catalog. 2237. Bibcode:2002yCat.2237....0D.
  3. 1 2 Samus', N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (January 2017). "General catalogue of variable stars: Version GCVS 5.1". Astronomy Reports. 61 (1): 80–88. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. eISSN   1562-6881. ISSN   1063-7729. S2CID   125853869.
  4. 1 2 3 4 5 6 Kochukhov, O.; Bagnulo, S. (10 April 2006). "Evolutionary state of magnetic chemically peculiar stars". Astronomy and Astrophysics. 450 (2): 763–775. arXiv: astro-ph/0601461 . Bibcode:2006A&A...450..763K. doi: 10.1051/0004-6361:20054596 . eISSN   1432-0746. ISSN   0004-6361. S2CID   18596834.
  5. 1 2 Cowley, A.; Cowley, C.; Jaschek, M.; Jaschek, C. (April 1969). "A study of the bright stars. I. A catalogue of spectral classifications". The Astronomical Journal. 74: 375. Bibcode:1969AJ.....74..375C. doi: 10.1086/110819 . ISSN   0004-6256. S2CID   121555804.
  6. 1 2 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.
  7. 1 2 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.
  8. 1 2 Kervella, P.; Thévenin, F.; Di Folco, E.; Ségransan, D. (April 8, 2004). "The angular sizes of dwarf stars and subgiants: Surface brightness relations calibrated by interferometry". Astronomy & Astrophysics. 426 (1): 297–307. arXiv: astro-ph/0404180 . Bibcode:2004A&A...426..297K. doi: 10.1051/0004-6361:20035930 . eISSN   1432-0746. ISSN   0004-6361. S2CID   6077801.
  9. 1 2 3 4 Netopil, Martin; Paunzen, Ernst; Hümmerich, Stefan; Bernhard, Klaus (17 March 2017). "An investigation of the rotational properties of magnetic chemically peculiar stars". Monthly Notices of the Royal Astronomical Society. 468 (3): 2745–2756. arXiv: 1703.05218 . Bibcode:2017MNRAS.468.2745N. doi: 10.1093/mnras/stx674 . eISSN   1365-2966. ISSN   0035-8711. S2CID   119215348.
  10. 1 2 3 Anders, F.; et al. (August 2019). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18". Astronomy & Astrophysics. 628: A94. arXiv: 1904.11302 . Bibcode:2019A&A...628A..94A. doi: 10.1051/0004-6361/201935765 . eISSN   1432-0746. ISSN   0004-6361. S2CID   131780028.
  11. 1 2 Floquet, M. (August 1981). "Effective temperature of AP stars". Astronomy and Astrophysics. 101: 176–183. Bibcode:1981A&A...101..176F. ISSN   0004-6361.
  12. ↑ 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.
  13. ↑ "25 Sextantis". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved February 2, 2024.
  14. ↑ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 4 July 2024.
  15. ↑ Manfroid, J.; Renson, P. (July 1980). "Nouvelle Recherche de Periodes D'etoiles Ap Observees a l'ESO-V". Information Bulletin on Variable Stars. 1824: 1. Bibcode:1980IBVS.1824....1M. ISSN   0374-0676.
  16. ↑ Kholopov, P. N.; Samus', N. N.; Kukarkina, N. P.; Medvedeva, G. I.; Perova, N. B. (November 1981). "66th Name-List of Variable Stars". Information Bulletin on Variable Stars. 2042: 1. Bibcode:1981IBVS.2042....1K. ISSN   0374-0676.
  17. ↑ Manfroid, J.; Mathys, G. (March 1985). "New period determinations for variable CP stars". Astronomy and Astrophysics Supplement Series. 59: 429–432. Bibcode:1985A&AS...59..429M. ISSN   0365-0138.
  18. ↑ Bohlender, D. A.; Landstreet, J. D.; Thompson, Ian B. (March 1993). "A study of magnetic fields in AP SI and He weak stars". Astronomy and Astrophysics. 269: 355–376. Bibcode:1993A&A...269..355B. ISSN   0004-6361.
  19. ↑ Leone, F.; Catanzaro, G. (2001). "Spectropolarimetric measurements of the mean longitudinal magnetic field of chemically peculiar stars: II. Phase relating the magnetic and luminosity variabilities". Astronomy & Astrophysics. 365 (2): 118–127. Bibcode:2001A&A...365..118L. doi: 10.1051/0004-6361:20000450 . ISSN   0004-6361.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.