Astronomy:V4024 Sagittarii
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Sagittarius |
| Right ascension | 19h 08m 16.70187s[2] |
| Declination | −19° 17′ 25.0380″[2] |
| Apparent magnitude (V) | 5.34 - 5.60[3] |
| Characteristics | |
| Spectral type | B2Ve[4] |
| B−V color index | −0.06[5] |
| Variable type | γ Cas[3] |
| Astrometry | |
| Radial velocity (Rv) | −20.3±2.9[6] km/s |
| Proper motion (μ) | RA: +6.240[2] mas/yr Dec.: −1.126[2] mas/yr |
| Parallax (π) | 2.3734 ± 0.1406[2] mas |
| Distance | 1,370 ± 80 ly (420 ± 20 pc) |
| Absolute magnitude (MV) | −2.39[6] |
| Details[7] | |
| Mass | 8.8±0.6 M☉ |
| Radius | 4.5[8] R☉ |
| Luminosity (bolometric) | 7,551+1,119 −974 L☉ |
| Surface gravity (log g) | 3.24±0.49 cgs |
| Temperature | 18,100±500 K |
| Rotational velocity (v sin i) | 105±10 km/s |
| Age | 25.1±1.3[9] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
V4024 Sagittarii is a single[11] 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.[12]
This object is a massive Be star with a stellar classification of B2Ve.[4] The 'e' suffix indicates the spectrum of the star displays emission lines, which are created by materials ejected from the equatorial region of this rapidly rotating star. It is classified as an eruptive Gamma Cassiopeiae variable and has been measured ranging in brightness from visual magnitude 5.34 down to 5.60.[3] The star is an estimated 5 million years old with 8.8 times the mass of the Sun[9] and about 4.5[8] times the Sun's radius. It is spinning with a projected rotational velocity of 105 m/s. V4024 Sagittarii is radiating 7,551 times the luminosity of the Sun from its photosphere at an effective temperature of 18,100 K.[7] Koen and Eyer examined the Hipparcos data for this star, and found that its brightness varied with a period of 1.7733 days.[13]
References
- ↑ "/ftp/cats/more/HIP/cdroms/cats". Strasbourg astronomical Data Center. https://cdsarc.cds.unistra.fr/viz-bin/ftp-index?/ftp/cats/more/HIP/cdroms/cats.
- ↑ 2.0 2.1 2.2 2.3 2.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 3.0 3.1 3.2 Samus, N. N. et al. (2017). "General Catalogue of Variable Stars". Astronomy Reports. 5.1 61 (1): 80–88. doi:10.1134/S1063772917010085. Bibcode: 2017ARep...61...80S.
- ↑ 4.0 4.1 Jaschek, C.; Jaschek, M. (November 1992). "A southern Be star survey: Spectra and envelope radii". Astronomy and Astrophysics Supplement Series 95 (3): 535–540. Bibcode: 1992A&AS...95..535J.
- ↑ Chauville, J. et al. (November 2001). "High and intermediate-resolution spectroscopy of Be stars 4481 lines". Astronomy and Astrophysics 378: 861–882. doi:10.1051/0004-6361:20011202. Bibcode: 2001A&A...378..861C.
- ↑ 6.0 6.1 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A.
- ↑ 7.0 7.1 Zorec, J. et al. (November 2016), "Critical study of the distribution of rotational velocities of Be stars. I. Deconvolution methods, effects due to gravity darkening, macroturbulence, and binarity", Astronomy & Astrophysics 595: 26, doi:10.1051/0004-6361/201628760, Bibcode: 2016A&A...595A.132Z
- ↑ 8.0 8.1 Pasinetti Fracassini, L. E. et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics 367 (2): 521–524, doi:10.1051/0004-6361:20000451, Bibcode: 2001A&A...367..521P.
- ↑ 9.0 9.1 Tetzlaff, N. et al. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society 410 (1): 190–200, doi:10.1111/j.1365-2966.2010.17434.x, Bibcode: 2011MNRAS.410..190T.
- ↑ "HD 178175". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+178175.
- ↑ Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society 389 (2): 869–879. doi:10.1111/j.1365-2966.2008.13596.x. Bibcode: 2008MNRAS.389..869E.
- ↑ Mason, Brian D. (November 1996). "ICCD Speckle Observations of Binary Stars. XV. An Investigation of Lunar Occultation Systems". Astronomical Journal 112: 2260. doi:10.1086/118179. Bibcode: 1996AJ....112.2260M.
- ↑ Koen, Chris; Eyer, Laurent (March 2002). "New periodic variables from the Hipparcos epoch photometry". Monthly Notices of the Royal Astronomical Society 331 (1): 45–59. doi:10.1046/j.1365-8711.2002.05150.x. Bibcode: 2002MNRAS.331...45K.
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