Alpha Equulei
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| Observation data Epoch J2000.0 |
|
|---|---|
| Constellation (pronunciation) |
Equuleus |
| Right ascension | 21h 15m 49.40s |
| Declination | +5° 14' 53.1" |
| Apparent magnitude (V) | +3.92 |
| Absolute magnitude (V) | +0.14 |
| Distance | 186 ly (57.05 pc) |
| Spectral type | G0III+ |
| Other designations | |
Alpha Equulei (α Equ / α Equulei) is a star in the constellation Equuleus. It also has the traditional name Kitalpha or Kitalphar, which is a contraction of the Arabic title Qit'at al Faras (قطعة الفرس), meaning "Part of the Horse".
Alpha Equulei collectively belongs to spectral class G0III and has apparent magnitude +3.92 and a luminosity approximately 75 times that of the Sun. However, the star deceives. Alpha Equulei is a unique spectroscopic binary star consisting of two components. The two stellar components within the system are so close together that the class is mixed, G + A, two spectra present at the same time. The brighter of the two (by about 50%, 45 times brighter than the Sun) is a class G (G0) giant, the fainter a white class A (A5) dwarf. The giant is in the process of dying and most likely (like the dimmer component of Capella) has a contracting helium core, while the dwarf is a common unevolved hydrogen-fuser. The blend of starlight makes actual temperatures difficult to measure, but should respectively be around 5500 and 8500 kelvins. The Kitalpa is approximately 186 light years from Earth.
[edit] References
- HD 202447 -- Spectroscopic binary. SIMBAD Astronomical Database. Retrieved on 2007-01-22.
