35 Sextantis (68 G. Sextantis; HD 92841; HR 4193), or simply 35 Sex, is a triple star system located in the equatorial constellation Sextans. The primary has an apparent magnitude of 6.09,[2] making it barely visible to the naked eye, even under ideal conditions. The companion has an apparent magnitude of 7.01,[2] 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.[17]
  | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Sextans |
| A | |
| Right ascension | 10h 43m 20.92086s[1] |
| Declination | +04° 44′ 51.6121″[1] |
| Apparent magnitude (V) | 6.09±0.01[2] |
| B | |
| Right ascension | 10h 43m 20.52732s[3] |
| Declination | +04° 44′ 48.2184″[3] |
| Apparent magnitude (V) | 7.01±0.01[2] |
| Characteristics | |
| U−B color index | +1.09[4] |
| B−V color index | +1.17[4] |
| A | |
| Spectral type | K2.5 III[5] |
| B | |
| Spectral type | K1 II-III[6] |
| Astrometry | |
| A | |
| Radial velocity (Rv) | −3.15±0.16[7] km/s |
| Proper motion (μ) | RA: +22.430 mas/yr[1] Dec.: −33.285 mas/yr[1] |
| Parallax (π) | 4.6773 ± 0.1457 mas[1] |
| Distance | 700 ± 20 ly (214 ± 7 pc) |
| B | |
| Radial velocity (Rv) | −1.49±0.98[7] km/s |
| Proper motion (μ) | RA: +24.384 mas/yr[3] Dec.: −37.384 mas/yr[3] |
| Parallax (π) | 4.5442 ± 0.15 mas[3] |
| Distance | 720 ± 20 ly (220 ± 7 pc) |
| Orbit[8] | |
| Primary | A |
| Companion | B |
| Period (P) | 23,302 yr |
| Semi-major axis (a) | 6.80" (1,460 AU) |
| Orbit[9] | |
| Primary | Ba |
| Companion | Bb |
| Period (P) | 1,568.7±2.2 d |
| Semi-major axis (a) | 0.021" (4.64 AU) |
| Eccentricity (e) | 0.388±0.057 |
| Periastron epoch (T) | 2,451,911±27 JD |
| Argument of periastron (ω) (secondary) | 311.8±3.3° |
| Semi-amplitude (K1) (primary) | 5.55±0.15 km/s |
| Details | |
| A | |
| Mass | 2.45[8] M☉ |
| Radius | 25.39+0.8 −2.2[10] R☉ |
| Luminosity | 240±7[10] L☉ |
| Temperature | 4,512±122[11] K |
| Metallicity [Fe/H] | −0.17[12] dex |
| Rotational velocity (v sin i) | 3.7±0.3[7] km/s |
| Ba | |
| Mass | 2.44[8] M☉ |
| Radius | 10.15+0.34 −0.30[13] R☉ |
| Luminosity | 57.2±1.2[13] L☉ |
| Temperature | 5,030±122[11] K |
| Metallicity [Fe/H] | −0.16[12] dex |
| Rotational velocity (v sin i) | 4.1±0.5[7] km/s |
| Bb | |
| Mass | 0.58[8] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | The system |
| A | |
| B | |
The System
edit| A | |||||||||||||||
| Separation = 6.8″ Period = 23,000 y | |||||||||||||||
| Ba | |||||||||||||||
| Separation = 0.021″ Period = 1,580 d | |||||||||||||||
| Bb | |||||||||||||||
Hierarchy of orbits in the 35 Sextantis system[9]
The system was first observed by Friedrich Georg Wilhelm von Struve in 1821.[18] The separation between the A and B component was initially 7.90 arcseconds,[18] but it has since decreased to 6.62".[19] Thanks to this separation, the components 35 Sextantis can be distinguished using a telescope. Observations from Tokovinin & Gorynya (2007) revealed that the B component is a single-lined spectroscopic binary.[9] The primary and secondary both take 23,302 years to orbit each other while the secondary and its close companion take 1,568 days to revolve around each other in a relatively eccentric orbit.[9]
Physical characteristic
edit35 Sextantis A has a stellar classification of K2.5 III,[5] indicating that it is an evolved K-type giant star that has exhausted hydrogen at its core and left the main sequence. 35 Sextantis B has a classification of K1 II-III,[6] indicating that it is a hotter, more evolved K-type star that has the luminosity class intermediate between a bright giant and giant star. The primary has 2.45 times the mass of the Sun[8] but it has expanded to 25.39 times the radius of the Sun.[10] It radiates 240 times the luminosity of the Sun[10] from its enlarged photosphere at an effective temperature of 4,512 K,[11] giving it an orange-hued when viewed in the night sky.
The secondary has a similar mass to the primary[8] but it is smaller, having a radius 10.15 times that of the Sun.[13] 35 Sextantis B radiates 57.2 times the luminosity of the Sun[13] from its photosphere at an effective temperature of 5030 K.[11] Both stars are metal deficient with iron abundances of [Fe/H] = −0.17 and [Fe/H] = −0.16 respectively.[12] They spin modestly with projected rotational velocities of 3.7 km/s and 4.1 km/s.[7] The close companion has a mass 58% that of the Sun's,[8] suggesting that it may be a K-type main-sequence star.
References
edit- ^ a b c d 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.
- ^ a b c d 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. S2CID 17128864.
- ^ a b c d 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.
- ^ a b 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.
- ^ a b Abt, H. A. (March 1981). "Visual multiples. VII - MK classifications". The Astrophysical Journal Supplement Series. 45: 437. Bibcode:1981ApJS...45..437A. doi:10.1086/190719. eISSN 1538-4365. ISSN 0067-0049. S2CID 121286745.
- ^ a b Lutz, T. E.; Lutz, J. H. (1977). "Spectral classification and UBV photometry of bright visual double stars". The Astronomical Journal. 82: 431. Bibcode:1977AJ.....82..431L. doi:10.1086/112066.
- ^ a b c d e Tokovinin, A. A.; Smekhov, M. G. (January 2002). "Statistics of spectroscopic sub-systems in visual multiple stars". Astronomy & Astrophysics. 382 (1): 118–123. Bibcode:2002A&A...382..118T. doi:10.1051/0004-6361:20011586. ISSN 0004-6361. S2CID 54823087.
- ^ a b c d e f g Tokovinin, A. (September 11, 2008). "Comparative statistics and origin of triple and quadruple stars". Monthly Notices of the Royal Astronomical Society. 389 (2): 925–938. arXiv:0806.3263. Bibcode:2008MNRAS.389..925T. doi:10.1111/j.1365-2966.2008.13613.x.
- ^ a b c d Tokovinin, A. A.; Gorynya, N. A. (April 2007). "New spectroscopic components in multiple systems. V." Astronomy & Astrophysics. 465 (1): 257–261. Bibcode:2007A&A...465..257T. doi:10.1051/0004-6361:20066888. ISSN 0004-6361. S2CID 34100030.
- ^ a b c d Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b c d 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. hdl:1721.1/124721. S2CID 166227927.
- ^ a b c 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.
- ^ a b c d Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ Verbunt, F.; van Gent, R. H. (June 2010). "The star catalogue of Hevelius: Machine-readable version and comparison with the modern Hipparcos Catalogue". Astronomy and Astrophysics. 516: A29. Bibcode:2010A&A...516A..29V. doi:10.1051/0004-6361/201014003. eISSN 1432-0746. ISSN 0004-6361. S2CID 54171435.
- ^ 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.
- ^ "* 35 Sex". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved January 21, 2024.
- ^ Famaey, B.; Jorissen, A.; Luri, X.; Mayor, M.; Udry, S.; Dejonghe, H.; Turon, C. (January 2005). "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters". Astronomy and Astrophysics. 430: 165. arXiv:astro-ph/0409579. Bibcode:2005A&A...430..165F. doi:10.1051/0004-6361:20041272. S2CID 17804304.
- ^ a b Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (December 2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466–3471. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. ISSN 0004-6256. S2CID 119533755.
- ^ Heintz, W. D. (July 1975). "Micrometer observations of double stars.8". The Astrophysical Journal Supplement Series. 29: 315. Bibcode:1975ApJS...29..315H. doi:10.1086/190345. ISSN 0067-0049. S2CID 119454231.