 Image showing DI Cha A and B, each of which is also an even closer binary, and the surrounding nebulosity. | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Chamaeleon |
| Right ascension | 11h 07m 20.72163s[1] |
| Declination | −77° 38′ 07.2903″[1] |
| Apparent magnitude (V) | 10.655[2] |
| Characteristics | |
| Spectral type | G0e[3] |
| U−B color index | +0.630[2] |
| B−V color index | +1.144[2] |
| Variable type | T Tau[4] |
| Astrometry | |
| Proper motion (μ) | RA: −24.61[1] mas/yr Dec.: 3.45[1] mas/yr |
| Parallax (π) | 4.49 ± 1.59 mas[1] |
| Distance | approx. 700 ly (approx. 220 pc) |
| Details[5] | |
| Aa | |
| Mass | 1.7 M☉ |
| Radius | 2.00 R☉ |
| Luminosity | 4.7 L☉ |
| Temperature | 6,030 K |
| Age | 7.1 Myr |
| Ba/Bb | |
| Mass | 0.18 M☉ |
| Radius | 1.13 R☉ |
| Luminosity | 0.11 L☉ |
| Temperature | 3,130 K |
| Age | 3.0 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
DI Chamaeleontis, also known as Hen 3-593 or HIP 54365, is a quadruple star system in the constellation Chamaeleon. The system is roughly 700 light years from Earth.
DI Cha is a variable star of the T Tauri type, young stellar objects just approaching the main sequence. It varies erratically between visual magnitudes 10.65 and 10.74.[4] Although it is visually faint, it was noticed because of the prominent emission lines in its spectrum.[6]
In 1977, DI Cha was observed to have a much fainter companion.[7] The separation was later measured at 4.6", approximately 644 astronomical units (AU).[8] The B component was discovered to be a pair of stars separated by only 0.066", about 10 AU,[9] both with spectral type M5.5.[10] Finally, the variable primary star was found to have a faint companion 0.2" (therefore ~30 AU) away, of spectral type M6.[10]
References
[edit]- ^ a b c d e Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600.
- ^ a b c Kilkenny, D.; Whittet, D. C. B.; Davies, J. K.; Evans, A.; Bode, M. F.; Robson, E. I.; Banfield, R. M. (1985). "Optical and infrared photometry of southern early-type shell stars and pre-main-sequence variables". In Its South African Astronomical Observatory Circular No. 9 P 55-86 (SEE N86-18271 08-89). 9: 55. Bibcode:1985SAAOC...9...55K.
- ^ Torres, C. A. O.; Quast, G. R.; Da Silva, L.; de la Reza, R.; Melo, C. H. F.; Sterzik, M. (2006). "Search for associations containing young stars (SACY). I. Sample and searching method". Astronomy and Astrophysics. 460 (3): 695. arXiv:astro-ph/0609258. Bibcode:2006A&A...460..695T. doi:10.1051/0004-6361:20065602. S2CID 16080025.
- ^ a b Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
- ^ Daemgen, S.; Petr-Gotzens, M. G.; Correia, S.; Teixeira, P. S.; Brandner, W.; Kley, W.; Zinnecker, H. (2013). "Protoplanetary disk evolution and stellar parameters of T Tauri binaries in Chamaeleon I". Astronomy & Astrophysics. 554: A43. arXiv:1304.1150. Bibcode:2013A&A...554A..43D. doi:10.1051/0004-6361/201321220. S2CID 59440639.
- ^ Henize, Karl G. (1963). "Emission-Line Stars in an Obscured Region in Chamaeleon". Astronomical Journal. 68: 280. Bibcode:1963AJ.....68S.280H. doi:10.1086/109141.
- ^ Schwartz, R. D. (1977). "A survey of southern dark clouds for Herbig-Haro objects and H-alpha emission stars". Astrophysical Journal Supplement Series. 35: 161. Bibcode:1977ApJS...35..161S. doi:10.1086/190473.
- ^ Reipurth, Bo; Zinnecker, Hans (1993). "Visual binaries among pre-main sequence stars". Astronomy and Astrophysics. 278: 81. Bibcode:1993A&A...278...81R.
- ^ Lafrenière, David; Jayawardhana, Ray; Brandeker, Alexis; Ahmic, Mirza; Van Kerkwijk, Marten H. (2008). "A Multiplicity Census of Young Stars in Chamaeleon I". The Astrophysical Journal. 683 (2): 844–861. arXiv:0803.0561. Bibcode:2008ApJ...683..844L. doi:10.1086/590239. S2CID 2998049.
- ^ a b Schmidt, T. O. B.; Vogt, N.; Neuhäuser, R.; Bedalov, A.; Roell, T. (2013). "New companions in the stellar systems of DI Cha, Sz 22, CHXR 32, and Cha Hα 5 in the Chamaeleon I star-forming region". Astronomy & Astrophysics. 557: A80. arXiv:1307.1082. Bibcode:2013A&A...557A..80S. doi:10.1051/0004-6361/201220660. S2CID 67802847.
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