44 Boötis
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| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Boötes |
| Right ascension | 15h 03m 47.304s |
| Declination | +47° 39′ 14.616″ |
| Apparent magnitude (V) | 4.75 |
| Characteristics | |
| Spectral type | G0Vnv |
| U−B color index | 0.11 |
| B−V color index | 0.65 |
| Variable type | W UMa variable |
| Astrometry | |
| Radial velocity (Rv) | -30.8 km/s |
| Proper motion (μ) | RA: -436.26 mas/yr Dec.: 18.93 mas/yr |
| Parallax (π) | 78.39 ± 1.03 mas |
| Distance | 41.6 ± 0.5 ly (12.8 ± 0.2 pc) |
| Absolute magnitude (MV) | 5.41 |
| Details | |
| Mass | 1.1/1+0.79 M☉ |
| Radius | 1.1/0.89+0.66 R☉ |
| Luminosity | 1.2/1 L☉ |
| Temperature | 5900/5500+5000 K |
| Rotation | <= 16 km/s 0,0095423 Year |
| Age | (1.4–1.5) × 109[1] years |
| Orbit | |
| Companion | 44 Boötis B |
| Period (P) | 225 yr |
| Semimajor axis (a) | 3.772" |
| Eccentricity (e) | 0.43 |
| Inclination (i) | 83.9° |
| Longitude of the node (Ω) | 57.8° |
| Periastron epoch (T) | 2021 |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Data sources: | |
| Hipparcos Catalogue, CCDM (2002), Bright Star Catalogue (5th rev. ed.) |
|
44 Boötis or i Boötis is a triple star system in the constellation Boötes. It is approximately 41.6 light years from Earth.
The primary component, 44 Boötis A, is a yellow-white F-type main sequence dwarf with a mean apparent magnitude of +4.83. The companion component, 44 Boötis B, is a W Ursae Majoris variable spectroscopic binary. The brightness of the binary varies from magnitude +5.8 to +6.40 with a period of 6.43 hours. The components of the eclipsing binary are separated by 0.008 Astronomical Units, roughly 3 times the distance of the Moon from Earth.
[edit] A substellar companion?
Recent analysis in timing variations for 44 Bootis B would suggest the presence of a third body orbiting the W Ursae Majoris-type eclipsing binary with likely substellar mass.[2] Its minimum mass is estimated at 48 times that of Jupiter and the orbital separation at 10.73 AUs (a bit farther away than Saturn in the Solar System). So far unconfirmed, such an object seems unstable considering the system's architecture, with 44 Bootis B-C getting as close as 26.6 AUs to 44 Bootis A,[3] unless it is locked in some kind of peculiar configuration and inclination.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (years) |
Eccentricity |
|---|---|---|---|---|
| b (unconfirmed) | ≥47.5 MJ | 10.73 | ≈35 | ? |
[edit] References
- ^ Mamajek, Eric E.; Hillenbrand, Lynne A. (November 2008). "Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics". The Astrophysical Journal 687 (2): 1264–1293. Bibcode 2008ApJ...687.1264M. doi:10.1086/591785.
- ^ a b Byrd-Fisher et al. (2008). "Patterns in the Long Term Behavior of Eclipsing Binary Star System 44i-Bootis". American Physical Society, 10th Annual Meeting of the Northwest Section of APS, May 15–17, 2008. Bibcode 2008APS..NWS.C1013B.
- ^ Heintz (1997). "Orbits of 40 Visual Binaries". Astrophysical Journal Supplement 111: 1–4. Bibcode 1997ApJS..111..335H. doi:10.1086/313011.
[edit] External links
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