Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Canis Major |
Right ascension | 07h 27m 07.99012s[2] |
Declination | −17° 51′ 53.5058″[2] |
Apparent magnitude (V) | 5.60[3] (5.66 + 9.23)[4] |
Characteristics | |
Spectral type | F2V[5] |
B−V color index | +0.314±0.002[3] |
Variable type | δ Sct[6] |
Astrometry | |
Radial velocity (Rv) | −29.2±2.9[3] km/s |
Proper motion (μ) | RA: −2.420[2] mas/yr Dec.: +1.388[2] mas/yr |
Parallax (π) | 10.9688 ± 0.0917 mas[2] |
Distance | 297 ± 2 ly (91.2 ± 0.8 pc) |
Absolute magnitude (MV) | 0.78[3] |
Details | |
A | |
Mass | 1.62[7] or 2.18±0.04[8] M☉ |
Radius | 3.90+0.18 −0.24[2] R☉ |
Luminosity | 37.4±0.4[2] L☉ |
Surface gravity (log g) | 3.65[7] cgs |
Temperature | 7,227+238 −160[2] K |
Rotational velocity (v sin i) | 185[9] km/s |
Age | 1.494[7] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
NR Canis Majoris is a binary star[11] system in the southern constellation of Canis Major, located to the east of Sirius and Gamma Canis Majoris near the constellation border with Puppis. It has a yellow-white hue and is dimly visible to the naked eye with a combined apparent visual magnitude that fluctuates around 5.60.[3] It is located at a distance of approximately 297 light years from the Sun based on parallax.[2] The system is drifting closer to the Sun with a radial velocity of −29 km/s,[3] and in about three million years it is predicted to approach within 14.1+4.7
−4.0 ly.[12] At that time, the star will become the brightest in the night sky, potentially reaching magnitude −0.88.[13]
The magnitude 5.66[4] primary component is an F-type main-sequence star with a stellar classification of F2V.[5] It is a Delta Scuti variable[6] that varies by a few hundredths of a magnitude over roughly 16 hours.[14] The star is an estimated 1.5 billion years old.[7] It has a high rate of spin with a projected rotational velocity of 185 km/s, which is giving the star an equatorial bulge that is estimated to be 8% larger than the polar radius.[9]
The secondary companion is magnitude 9.23 and lies at an angular separation of 1.3″ along a position angle of 39°, as of 2005.[4]
References
[edit]- ^ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 8 December 2021.
- ^ a b c d e f g h i 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 e f 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 c Mason, B. D.; et al. (2014). "The Washington Visual Double Star Catalog". The Astronomical Journal. 122 (6): 3466. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. Retrieved 2015-07-22.
- ^ a b Houk, Nancy; Smith-Moore, M. (1978). Michigan catalogue of two-dimensional spectral types for the HD stars. Vol. 4. Ann Arbor: Department of Astronomy, University of Michigan. Bibcode:1988mcts.book.....H.
- ^ a b Samus, N. N.; et al. (2017). "General Catalogue of Variable Stars". Astronomy Reports. 5.1. 61 (1): 80–88. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. S2CID 125853869.
- ^ a b c d David, Trevor J.; Hillenbrand, Lynne A. (2015). "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets". The Astrophysical Journal. 804 (2): 146. arXiv:1501.03154. Bibcode:2015ApJ...804..146D. doi:10.1088/0004-637X/804/2/146. S2CID 33401607.
- ^ Zorec, J.; Royer, F. (2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". Astronomy & Astrophysics. 537: A120. arXiv:1201.2052. Bibcode:2012A&A...537A.120Z. doi:10.1051/0004-6361/201117691. S2CID 55586789.
- ^ a b van Belle, Gerard T. (March 2012). "Interferometric observations of rapidly rotating stars". The Astronomy and Astrophysics Review. 20 (1): 51. arXiv:1204.2572. Bibcode:2012A&ARv..20...51V. doi:10.1007/s00159-012-0051-2. S2CID 119273474.
- ^ "NR CMa". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 12 February 2017.
- ^ 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. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. S2CID 14878976.
- ^ Bailer-Jones, C. A. L. (March 2015). "Close encounters of the stellar kind". Astronomy & Astrophysics. 575: 13. arXiv:1412.3648. Bibcode:2015A&A...575A..35B. doi:10.1051/0004-6361/201425221. S2CID 59039482. A35.
- ^ Tomkin, Jocelyn (April 1998). "Once and Future Celestial Kings". Sky and Telescope. 95 (4): 59–63. Bibcode:1998S&T....95d..59T.
- ^ Watson, Christopher (4 January 2010). "LS Canis Majoris". AAVSO Website. American Association of Variable Star Observers. Retrieved 12 July 2014.
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