Astronomy:HD 98088
  | |
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Crater[1] |
| Right ascension | 11h 16m 58.177s[2] |
| Declination | –07° 08′ 04.870″[2] |
| Apparent magnitude (V) | 6.11[1] |
| Characteristics | |
| Spectral type | A8 Sr Cr Eu[3] A3Vp + A8V[4] |
| B−V color index | 0.211±0.008[1] |
| Variable type | α2 CVn[5] |
| Astrometry | |
| Radial velocity (Rv) | −8.65±0.29[4] km/s |
| Proper motion (μ) | RA: −8.221[2] mas/yr Dec.: +8.458[2] mas/yr |
| Parallax (π) | 7.88 ± 0.0566[2] mas |
| Distance | 414 ± 3 ly (126.9 ± 0.9 pc) |
| Absolute magnitude (MV) | 0.56[1] |
| Orbit[4] | |
| Period (P) | 5.9051102±0.0000023 d |
| Eccentricity (e) | 0.1840±0.0025 |
| Inclination (i) | 69±2° |
| Periastron epoch (T) | 2434401.369±0.015 JD |
| Semi-amplitude (K1) (primary) | 73.31±0.26 km/s |
| Semi-amplitude (K2) (secondary) | 100.70±0.43 km/s |
| Details | |
| Primary | |
| Mass | 2.19±0.07[4] M☉ |
| Radius | 2.76±0.28[4] R☉ |
| Luminosity | 32.4+4.8−4.2[4] L☉ |
| Surface gravity (log g) | 3.90±0.09[4] cgs |
| Temperature | 8,030±120[3] K |
| Age | 646+96−83[4] Myr |
| Secondary | |
| Mass | 1.67±0.08[4] M☉ |
| Radius | 1.77±0.24[4] R☉ |
| Luminosity | 8.9+2.3−1.8[4] L☉ |
| Surface gravity (log g) | 4.16±0.12[4] cgs |
| Temperature | 7,500±300[4] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 98088 is a close binary star system of chemically peculiar stars[4] in the southern constellation of Crater.[1] It has the variable star designation SV Crt and is sometimes called "Abt's star" after Helmut Abt.[7] With an apparent visual magnitude that varies around 6.11,[1] it is faintly visible to the naked eye. Based on parallax measurements, it is located at a distance of 414 light-years (126.9 pc).
Observations
In 1950, as part of a survey of 2,111 stars, Ralph E. Wilson and Alfred H. Joy found a radial velocity of −55 km/s and a stellar classification of gFop for HD 98088. They noted that one of their spectroscopic plates showed double lines, and a line of ionized strontium appeared abnormally strong.[8]
Helmut A. Abt took an interest in this star and decided to investigate. He found a variation in the radial velocity with a period of 5.905±0.005 d, suggesting this is a binary system.[9] In 1958, Horace W. Babcock identified it as a short period spectroscopic binary with a magnetic field. He found a class of A2p with anomalous line intensities for strontium, barium, and titanium. The magnetic field varied in intensity in a manner which resembled that in α2 Canum Venaticorum.[10]
In 1968, Abt and associates determined that the Ap component of this double-lined spectroscopic binary is a main sequence star with about 2.2 times the mass of the Sun. Its companion is fainter by 1.2 magnitudes, suggesting a spectral type of A8V. The rotation of the primary appears aligned with its orbital period so that one side constantly faces its companion. The system is not eclipsing, but the orbit is inclined at an angle of about 67° to the plane of the sky.[11] In 1973, H. M. Maitzen demonstrated the system varied regularly in visual light, with the primary minimum occurring when the lines of strontium and europium were at maximum strength.[12]
In 2002, F. Carrier and associates published revised orbital elements based on CORAVEL velocimeter measurements. These were consistent with the earlier elements by Abt. Of interest is that the system shows a significant orbital eccentricity despite the close orbit. This suggested that apsidal motion should occur, but observations indicates the period must be a millennium or longer.[13] Abundance analysis of the system in 2013 showed that the secondary component is an Am star. This makes it a rare example of a tidally locked binary system in which both components are chemically peculiar, and one is an Ap star.[4]
The system has a pair of visual companions.[9]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A. XHIP record for this object at VizieR.
- ↑ 2.0 2.1 2.2 2.3 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940. Gaia DR3 record for this source at VizieR.
- ↑ 3.0 3.1 Paunzen, E. (June 2013), "Search for rapid oscillations among seven northern CP stars", Information Bulletin on Variable Stars 6058: 1, Bibcode: 2013IBVS.6058....1P.
- ↑ 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 4.11 4.12 4.13 4.14 Folsom, C. P. (May 2013), "Orbital parameters, chemical composition and magnetic field of the Ap binary HD 98088", Monthly Notices of the Royal Astronomical Society 431 (2): 1513–1527, doi:10.1093/mnras/stt269, Bibcode: 2013MNRAS.431.1513F.
- ↑ Samus, N. N.; Kazarovets, E. V. et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1 61 (1): 80–88, doi:10.1134/S1063772917010085, Bibcode: 2017ARep...61...80S.
- ↑ "HD 98088". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+98088.
- ↑ Matthews, J. M.; Wehlau, W. H. (September 1985), "A search for rapid variability among four northern AP stars", Publications of the Astronomical Society of the Pacific 97: 841–846, doi:10.1086/131612, Bibcode: 1985PASP...97..841M.
- ↑ Wilson, Ralph E.; Joy, Alfred H. (March 1950), "Radial Velocities of 2111 Stars", Astrophysical Journal 111: 221, doi:10.1086/145261, Bibcode: 1950ApJ...111..221W.
- ↑ 9.0 9.1 Abt, Helmut A. (December 1953), "Radial Velocity and Spectrum of HD 98088", Publications of the Astronomical Society of the Pacific 65 (387): 274, doi:10.1086/126622, Bibcode: 1953PASP...65..274A.
- ↑ Babcock, Horace W. (September 1958), "Magnetic Fields of the A-Type Stars", Astrophysical Journal 128: 228, doi:10.1086/146539, Bibcode: 1958ApJ...128..228B.
- ↑ "The Mass and Other Characteristics of the Magnetic Star HD 98088", Astrophysical Journal 153: 177, July 1968, doi:10.1086/149648, Bibcode: 1968ApJ...153..177A.
- ↑ "Photoelectric observations of the AP star HD 98088", Astronomy and Astrophysics Supplement 11: 327, September 1973, Bibcode: 1973A&AS...11..327M.
- ↑ Carrier, F. (October 2002), "Multiplicity among chemically peculiar stars. II. Cool magnetic Ap stars", Astronomy and Astrophysics 394: 151–169, doi:10.1051/0004-6361:20021122, Bibcode: 2002A&A...394..151C.
Further reading
- Glagolevskij, Yu. V. (2025), "Structure of Magnetic Fields of Primary Components of Close Binary Systems BD-19 5044L, HD 37017, HD 98088", Astrophysical Bulletin 80 (3): 418–427, doi:10.1134/S1990341325600425, Bibcode: 2025AstBu..80..418G.
- Hensberge, G. (June 1974), "Detection of Crossover Effect in the AP Star HD 98088", Astronomy and Astrophysics 32: 457, Bibcode: 1974A&A....32..457H.
 |  |
