Epoch J2000 Equinox J2000
|Right ascension||14h 05m 19.87784s|
|Declination||–76° 47′ 48.3204″|
|Apparent magnitude (V)||5.7|
|Spectral type||M7 III|
|U−B color index||+1.07|
|B−V color index||+1.48|
|Variable type||Semiregular pulsating|
|Radial velocity (Rv)||+9.0 km/s|
|Proper motion (μ)||RA: –87.54 mas/yr
Dec.: –32.54 mas/yr
|Parallax (π)||8.84 ± 0.49 mas|
|Distance||370 ± 20 ly
(113 ± 6 pc)
|Absolute magnitude (MV)||0.7|
Theta Apodis (θ Aps, θ Apodis) is the Bayer designation for a star in the southern circumpolar constellation of Apus. It is a variable star with a mean apparent visual magnitude of 5.7, which, according to the Bortle Dark-Sky Scale, means it is a faint star but visible to the naked eye from dark suburban skies. The distance to Theta Apodis is approximately 370 light-years (110 parsecs), based upon parallax measurements made from the Hipparcos spacecraft. It is unusual in that it is a red star with a high proper motion (greater than 50 milliarcseconds a year).
This is an evolved red giant that is currently on the asymptotic giant branch, with a stellar classification of M7 III. It shines with a luminosity approximately 3879 times that of the Sun and has a surface temperature of 3151 K. It is a semiregular pulsating variable and its brightness changes over a range of 0.56 magnitudes with a period of 119 days. It is losing mass at the rate of 1.1 × 10−7 times the mass of the Sun per year through its stellar wind. Dusty material ejected from this star is interacting with the surrounding interstellar medium, forming a bow shock as the star moves through the galaxy. The stand-off distance for this front is located at about 0.134 ly (0.041 pc) from Theta Apodis.
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