  | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Circinus |
| Right ascension | 15h 16m 56.89591s[1] |
| Declination | −60° 57′ 26.1201″[1] |
| Apparent magnitude (V) | 5.09[2] (5.05 - 5.20[3]) |
| Characteristics | |
| Spectral type | O7.5III(f)[3] (O8IV[3] + O9.5V + B0.5V([4]) |
| U−B color index | −0.88[2] |
| B−V color index | −0.06[2] |
| Variable type | Eclipsing and ellipsoidal[3] |
| Astrometry | |
| Radial velocity (Rv) | −17.80[5] km/s |
| Proper motion (μ) | RA: −4.085[1] mas/yr Dec.: −3.758[1] mas/yr |
| Parallax (π) | 1.4345 ± 0.1231 mas[1] |
| Distance | 2,300 ± 200 ly (700 ± 60 pc) |
| Orbit[3] | |
| Primary | Aa |
| Companion | Ab |
| Period (P) | 3.902463 days |
| Semi-major axis (a) | 34.7 R☉ |
| Eccentricity (e) | 0.068 |
| Inclination (i) | 75.81° |
| Semi-amplitude (K1) (primary) | 156.8 km/s |
| Semi-amplitude (K2) (secondary) | 280.4 km/s |
| Orbit[3] | |
| Primary | Aab |
| Companion | Ac |
| Period (P) | 1,644 days |
| Semi-major axis (a) | 3.87″ |
| Eccentricity (e) | 0.415 |
| Inclination (i) | 87.7° |
| Semi-amplitude (K1) (primary) | 23.6 km/s |
| Details | |
| Aa | |
| Mass | 20.00±0.50[6] M☉ |
| Radius | 9.256±0.091[6] R☉ |
| Luminosity | 153,000+27,000 −23,000 L☉ |
| Surface gravity (log g) | 3.806[6] cgs |
| Temperature | 37,500[6] K |
| Rotational velocity (v sin i) | 150±9[4] km/s |
| Ab | |
| Mass | 11.41±0.24[6] M☉ |
| Radius | 5.326±0.091[6] R☉ |
| Luminosity | 21,827+5,026 −4,085[6] L☉ |
| Surface gravity (log g) | 4.043±0.014[6] cgs |
| Temperature | 30,400±400[6] K |
| Rotational velocity (v sin i) | 141±230[4] km/s |
| Ac | |
| Mass | 18.7[3] M☉ |
| Luminosity | 17,000[3] L☉ |
| Surface gravity (log g) | 4.2[3] cgs |
| Temperature | 28,000[3] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
Delta Circini (δ Cir), is a multiple star system located in the constellation Circinus. Delta Circini is also known as HR 5664, and HD 135240. The system has a combined apparent visual magnitude of +5.09, and is located at a distance of about 700 pc (2,300ly) from the Sun.
- ^ 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 Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
- ^ a b c d e f g h i j Cite error: The named reference
mayerwas invoked but never defined (see the help page). - ^ a b c Penny, Laura R.; Seyle, Debra; Gies, Douglas R.; Harvin, James A.; Bagnuolo, William G.; Thaller, M. L.; Fullerton, A. W.; Kaper, L. (2001). "Tomographic Separation of Composite Spectra. VII. The Physical Properties of the Massive Triple System HD 135240 (δ Circini)". The Astrophysical Journal. 548 (2): 889. Bibcode:2001ApJ...548..889P. doi:10.1086/319031.
- ^ Pourbaix, D.; Tokovinin, A. A.; Batten, A. H.; Fekel, F. C.; Hartkopf, W. I.; Levato, H.; Morrell, N. I.; Torres, G.; Udry, S. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits". Astronomy and Astrophysics. 424 (2): 727–732. arXiv:astro-ph/0406573. Bibcode:2004A&A...424..727P. doi:10.1051/0004-6361:20041213. S2CID 119387088.
- ^ a b c d e f g h i Southworth, John; Bowman, Dominic M. (July 2022). "High-mass pulsators in eclipsing binaries observed using TESS". Monthly Notices of the Royal Astronomical Society. 513 (3): 3191–3209. arXiv:2203.15365. Bibcode:2022MNRAS.513.3191S. doi:10.1093/mnras/stac875.