  | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Ophiuchus |
| Right ascension | 17h 47m 53.55973s[1] |
| Declination | +02° 42′ 26.2000″[1] |
| Apparent magnitude (V) | +3.753[2] |
| Characteristics | |
| Spectral type | A0 V[3] or A1VnkA0mA0[4] |
| U−B color index | +0.040[2] |
| B−V color index | +0.033[2] |
| Astrometry | |
| Radial velocity (Rv) | −7.6±0.3[5] km/s |
| Proper motion (μ) | RA: −24.64[1] mas/yr Dec.: −74.42[1] mas/yr |
| Parallax (π) | 31.73 ± 0.21 mas[1] |
| Distance | 102.8 ± 0.7 ly (31.5 ± 0.2 pc) |
| Absolute magnitude (MV) | +1.26[5] |
| Details | |
| Mass | 2.9[3] M☉ |
| Radius | 1.8[6] R☉ |
| Luminosity | 29[3] L☉ |
| Surface gravity (log g) | 4.03[4] cgs |
| Temperature | 9,506[3] K |
| Rotational velocity (v sin i) | 220[7] km/s |
| Age | 184+93 −134[7] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Gamma Ophiuchi, Latinized from γ Ophiuchi, is a fourth-magnitude star in the constellation Ophiuchus. Together with Beta Ophiuchi, it forms the serpent-holder's right shoulder.[10] The staris visible to the naked eye with an apparent visual magnitude of +3.75.[2] Based upon an annual parallax shift of 31.73 mas as seen from Earth, it is located 103 light years from the Sun. It is moving closer to the Sun with a radial velocity of −7.6 km/s.[5]
It is known also as Muliphen,[8][11] although at least two more stars are known with this name: Gamma Canis Majoris (often spelled as Muliphein) and Gamma Centauri (often spelled as Muhlifain).[11]
This is an A-type main sequence star with a stellar classification of A0 V.[3] Gray et al. (2003) lists a classification of A1VnkA0mA0,[4] indicating it is of type A1 V with the calcium K-line and metallic lines of an A0 star. It is approximately 184[7] million years old and is spinning rapidly with a projected rotational velocity of 220 km/s.[7] Gamma Ophiuchi has nearly three times the mass of the Sun and 1.8 times the Sun's radius.[6] The star shines with 29[3] times the luminosity of the Sun, which is being emitted from its outer atmosphere at an effective temperature of 9506 K.[3] It is radiating an excess emission of infrared, suggesting the presence of a circumstellar disk of dust at an orbital radius of 64 AU from the host star.[3]
References
[edit]- ^ a b c d e van Leeuwen, F. (2007). "Validation of the New Hipparcos Reduction". Astronomy and Astrophysics. 474 (2): 653–64. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600.
- ^ a b c d Cousins, A. W. J. (1984), "Standardisation of broad band photometry of equatorial standards", South Africa Astronomical Observatory Circular, 8: 59–67, Bibcode:1984SAAOC...8...59C.
- ^ a b c d e f g h Wyatt, M. C.; et al. (July 2007), "Steady State Evolution of Debris Disks around A Stars", The Astrophysical Journal, 663 (1): 365–382, arXiv:astro-ph/0703608, Bibcode:2007ApJ...663..365W, doi:10.1086/518404, S2CID 18883195
- ^ a b c Gray, R. O.; Corbally, C. J.; Garrison, R. F.; McFadden, M. T.; Bubar, E. J.; McGahee, C. E.; O'Donoghue, A. A.; Knox, E. R. (2006). "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc--The Southern Sample". The Astronomical Journal. 132 (1): 161–170. arXiv:astro-ph/0603770. Bibcode:2006AJ....132..161G. doi:10.1086/504637. S2CID 119476992.
- ^ a b c Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ^ a b Malagnini, M. L.; Morossi, C. (November 1990), "Accurate absolute luminosities, effective temperatures, radii, masses and surface gravities for a selected sample of field stars", Astronomy and Astrophysics Supplement Series, 85 (3): 1015–1019, Bibcode:1990A&AS...85.1015M
- ^ a b c d Song, Inseok; et al. (February 2001), "Ages of A-Type Vega-like Stars from uvbyβ Photometry", The Astrophysical Journal, 546 (1): 352–357, arXiv:astro-ph/0010102, Bibcode:2001ApJ...546..352S, doi:10.1086/318269, S2CID 18154947
- ^ a b Hinckley Allen, Richard. "LacusCurtius • Allen's Star Names — Ophiuchus". Retrieved 2017-01-03.
- ^ "* gam Oph". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2007-01-20.
- ^ Ridpath, Ian (June 28, 2018), Star Tales, Lutterworth Press, p. 189, ISBN 9780718847821.
- ^ a b Kaler, Jim. "Muliphen". Retrieved 2017-01-03.
Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction