Astronomy:Zeta1 Scorpii
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Scorpius |
| Right ascension | 16h 53m 59.72713s[1] |
| Declination | −42° 21′ 43.3073″[1] |
| Apparent magnitude (V) | 4.705[2] (4.66 to 4.86)[3] |
| Characteristics | |
| Spectral type | B1.5 Ia+[4] |
| U−B color index | −0.567[2] |
| B−V color index | +0.480[2] |
| Variable type | Luminous blue variable[5] |
| Astrometry | |
| Radial velocity (Rv) | −26.0[6] km/s |
| Proper motion (μ) | RA: −0.094[1] mas/yr Dec.: −3.368[1] mas/yr |
| Parallax (π) | 0.5855 ± 0.1176[1] mas |
| Distance | approx. 6,000 ly (approx. 1,700 pc) |
| Absolute magnitude (MV) | −8.5[4] |
| Details | |
| Mass | 36 to 53[4] M☉ |
| Radius | 159+83 −34[7] R☉ |
| Luminosity (bolometric) | (1.0–1.6)×106[7] L☉ |
| Surface gravity (log g) | 1.7[4] cgs |
| Temperature | 17,000–19,000[7] K |
| Rotational velocity (v sin i) | 60[8] km/s |
| Age | 6.5±0.1[9] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Zeta1 Scorpii (Zeta1 Sco, ζ1 Scorpii, ζ1 Sco) is a binary star[7] in the constellation of Scorpius, composed by an B-type hypergiant star as the primary, and a secondary of which little is known. It has an apparent visual magnitude which varies between 4.66 and 4.86.[3] It is a member of the Scorpius OB1 association, and potentially of the open star cluster NGC 6231,[11] also known as the "Northern jewel box" cluster.
Characteristics
ζ1 Scorpii's primary is a luminous blue variable according to its luminosity and spectral appearance,[13] yet is has not shown the characteristic types of variability, hence is classified as a dormant LBV.[5] It has around 36 times as massive as the Sun[4] and is one of the most luminous stars known in the Galaxy, with an estimated bolometric luminosity between 1 and 1.6 million times that of the Sun and a radius around 160 times that of the Sun.[7] The stellar wind from this supergiant is expelling matter from the star at the rate of 1.55 × 10−6 solar masses per year, or roughly the equivalent to the Sun's mass every 640,000 years.[4]
The secondary has been detected using interferometry, and its discovery was announced in 2021. As of 2021[update], it has an angular separation of 11.54±0.10 mas along a position angle of 283.22°+0.76°
−0.34°. It is 6.3 magnitudes fainter than the primary.[7]
ζ1 Scorpii forms a naked eye double with ζ2 Scorpii, but the stars are merely coincidentally near in the line of sight from Earth. ζ2 is a mere 135 light-years distant and much less luminous in real terms. ζ1 Scorpii can also be distinguished from ζ2, due to the latter's orange hue especially in long-exposure photographs.
References
- ↑ 1.0 1.1 1.2 1.3 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.
- ↑ 2.0 2.1 2.2 Kozok, J. R. (September 1985). "Photometric observations of emission B-stars in the southern Milky Way". Astronomy and Astrophysics Supplement Series 61: 387–405. Bibcode: 1985A&AS...61..387K.
- ↑ 3.0 3.1 "Query= zet 1 Sco". Lomonosov Moscow State University. http://www.sai.msu.su/gcvs/cgi-bin/search.cgi?search=Zet+1+Sco.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 Clark, J. S.; Najarro, F.; Negueruela, I.; Ritchie, B. W.; Urbaneja, M. A.; Howarth, I. D. (2012). "On the nature of the galactic early-B hypergiants". Astronomy & Astrophysics 541: A145. doi:10.1051/0004-6361/201117472. Bibcode: 2012A&A...541A.145C.
- ↑ 5.0 5.1 Spejcher, Becca; Richardson, Noel D.; Pablo, Herbert; Beltran, Marina; Butler, Payton; Avila, Eddie (January 1, 2025). "An Investigation into the Variability of Luminous Blue Variable Stars with TESS" (in en). The Astronomical Journal 169 (3): 128. doi:10.3847/1538-3881/ada561. ISSN 1538-3881. Bibcode: 2025AJ....169..128S.
- ↑ Evans, D. S. (June 20–24, 1966). "The Revision of the General Catalogue of Radial Velocities". in Batten, Alan Henry; Heard, John Frederick. Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30. 30. University of Toronto: International Astronomical Union. pp. 57. Bibcode: 1967IAUS...30...57E.
- ↑ 7.0 7.1 7.2 7.3 7.4 7.5 Mahy, L.; Lanthermann, C.; Hutsemékers, D.; Kluska, J.; Lobel, A.; Manick, R.; Miszalski, B.; Reggiani, M. et al. (January 2022). "Multiplicity of Galactic luminous blue variable stars" (in en). Astronomy and Astrophysics 657: A4. doi:10.1051/0004-6361/202040062. ISSN 0004-6361. Bibcode: 2022A&A...657A...4M.
- ↑ Bernacca, P. L.; Perinotto, M. (1970). "A catalogue of stellar rotational velocities". Contributi Osservatorio Astronomico di Padova in Asiago 239 (1): 1. Bibcode: 1970CoAsi.239....1B.
- ↑ Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (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.
- ↑ HIP 82671 -- Emission-line Star, database entry, SIMBAD. Accessed on line November 20, 2009.
- ↑ "Zeta-1 Sco". http://stars.astro.illinois.edu/sow/zeta1sco.html.
- ↑ Sterken, C.; de Groot, M.; van Genderen, A. M. (October 1997). "Cyclicities in the light variations of LBVs I. The multi-periodic behaviour of the LBV candidate ζ1 Sco". Astronomy and Astrophysics 326: 640–646. Bibcode: 1997A&A...326..640S. https://ui.adsabs.harvard.edu/abs/1997A&A...326..640S. Retrieved 20 October 2022.
- ↑ Nazé, Y.; Rauw, G.; Hutsemékers, D. (2012). "The first X-ray survey of Galactic luminous blue variables". Astronomy & Astrophysics 538: A47. doi:10.1051/0004-6361/201118040. Bibcode: 2012A&A...538A..47N.
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