  | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Dorado |
| A | |
| Right ascension | 05h 26m 59.80322s[1] |
| Declination | −68° 37′ 21.1327″[1] |
| Apparent magnitude (V) | 6.62±0.01[2] |
| B | |
| Right ascension | 05h 26m 59.87970s[3] |
| Declination | −68° 37′ 22.4439″[3] |
| Apparent magnitude (V) | 6.91±0.01[2] |
| Characteristics | |
| Spectral type | F0 IV/V[4] |
| A | |
| B−V color index | +0.37[5] |
| B | |
| B−V color index | +0.40[5] |
| Astrometry | |
| Radial velocity (Rv) | −4.60±3.4[6] km/s |
| Absolute magnitude (MV) | +1.57[7] |
| A | |
| Proper motion (μ) | RA: −10.638 mas/yr[1] Dec.: −17.846 mas/yr[1] |
| Parallax (π) | 12.4037 ± 0.0261 mas[1] |
| Distance | 263.0 ± 0.6 ly (80.6 ± 0.2 pc) |
| B | |
| Proper motion (μ) | RA: −4.710 mas/yr[3] Dec.: −19.675 mas/yr[3] |
| Parallax (π) | 12.4171 ± 0.0384 mas[3] |
| Distance | 262.7 ± 0.8 ly (80.5 ± 0.2 pc) |
| Orbit[8] | |
| Period (P) | 795 yr |
| Semi-major axis (a) | 1.704″ |
| Eccentricity (e) | 0.887 |
| Inclination (i) | 129.5° |
| Longitude of the node (Ω) | 74.8° |
| Periastron epoch (T) | 2,403,927.97472 JD |
| Argument of periastron (ω) (secondary) | 112.8° |
| Details | |
| A | |
| Mass | 1.69[9] M☉ |
| B | |
| Mass | 1.57[9] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | the system |
| A | |
| B | |
HD 36584 (HR 1859; 24 G. Doradus) is a visual binary located in the southern constellation Dorado. The primary has an apparent magnitude of 6.62 and the secondary has an apparent magnitude of 6.91,[2] making both stars visible in a telescope but not to the naked eye. The system is located relatively close at a distance of 263 light-years based on Gaia DR3 parallax measurements[1][3] and it is drifting closer with a heliocentric radial velocity of −4.6 km/s.[6] The system has a combined absolute magnitude of 1.57.[7]
HD 36584 was first discovered to be a double star in 1898 by astronomer R.T.A Innes. At the time of discovery, the components had a separation of only half an arcsecond and the secondary was located at a position angle of 210°.[12] The separation between the components increased to 1.34" and the position angle of the secondary shifted to 162° in 1997. At this separation, the components can be resolved in an amateur telescope, but the individual characteristics of both stars cannot be studied. As of 2015, the secondary is located at a distance of 1.4" along a position angle of 159°.[13] The two stars take about 795 years to circle each other in a very eccentric orbit.[8]
The system has a combined stellar classification of F0 IV/V,[4] indicating that it is an evolved F-type star that has the blended luminosity class of a subgiant and main sequence star. The components have masses 1.69 and 1.57 times that of the Sun respectively.[9]
References
[edit]- ^ a b c d e 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 Fabricius, C.; Høg, E.; Makarov, V. V.; Mason, B. D.; Wycoff, G. L.; Urban, S. E. (March 2002). "The Tycho double star catalogue". Astronomy & Astrophysics. 384 (1): 180–189. Bibcode:2002A&A...384..180F. doi:10.1051/0004-6361:20011822. eISSN 1432-0746. ISSN 0004-6361.
- ^ a b c d e 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 Houk, N.; Cowley, A. P. (1975). University of Michigan Catalogue of two-dimensional spectral types for the HD stars: Declinations −90° to −53°. Vol. 1. Bibcode:1975mcts.book.....H.
- ^ a b Fabricius, C.; Makarov, V. V. (April 2000). "Two-colour photometry for 9473 components of close Hipparcos double and multiple stars". Astronomy and Astrophysics. 356: 141–145. Bibcode:2000A&A...356..141F. eISSN 1432-0746. ISSN 0004-6361.
- ^ a b Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35,495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. eISSN 1562-6873. ISSN 1063-7737. S2CID 119231169.
- ^ a b Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. eISSN 1562-6873. ISSN 1063-7737. S2CID 119257644.
- ^ a b Zirm, H. (June 2013). "Information Circular No. 180" (PDF). International Astronomical Union Commission 26. ISSN 1024-7769.
- ^ a b c Chulkov, Dmitry; Malkov, Oleg (October 20, 2022). "Visual binary stars with known orbits in Gaia EDR3". Monthly Notices of the Royal Astronomical Society. 517 (2): 2925–2941. arXiv:2206.00604. Bibcode:2022MNRAS.517.2925C. doi:10.1093/mnras/stac2827. ISSN 0035-8711. S2CID 249240123.
- ^ 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.
- ^ "HD 36584". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved February 26, 2024.
- ^ Gill, David; Astronomer, H. M. (June 1898). "Fifth list of new double stars". Astronomische Nachrichten. 146 (21): 369–372. Bibcode:1898AN....146..369G. doi:10.1002/asna.18981462104. ISSN 0004-6337.
- ^ 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.
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