R Apodis
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Apus |
| Right ascension | Template:RA[1] |
| Declination | Template:DEC[1] |
| Apparent magnitude (V) | 5.36±0.01[2] |
| Characteristics | |
| Spectral type | K4 III:[3] |
| B−V Template:Engvar | +1.44[4] |
| Variable type | constant[5] |
| Astrometry | |
| Radial velocity (Rv) | −31.20±0.08[6] km/s |
| Proper motion (μ) | RA: −69.161 mas/yr[1] Dec.: −16.583 mas/yr[1] |
| Parallax (π) | 7.8879±0.0867 mas[1] |
| Distance | Template:Rnd ± Template:Rnd ly (Template:Rnd ± Template:Rnd pc) |
| Absolute magnitude (MV) | −0.22±0.16[7] |
| Details[6] | |
| Mass | Template:Val Template:Solar mass |
| Radius | Template:Val[1] Template:Solar radius |
| Luminosity | Template:Val[1] Template:Solar luminosity |
| Surface gravity (log g) | Template:Val cgs |
| Temperature | Template:Val K |
| Metallicity [Fe/H] | Template:Val dex |
| Rotational velocity (v sin i) | Template:Val km/s |
| Age | Template:Val Gyr |
| Metallicity [Fe/H] | {{{metal_fe2}}} dex |
| Other designations | |
| Template:Odlist | |
| Database references | |
| SIMBAD | data |
Script error: No such module "Check for unknown parameters".
R Apodis (HD 131109; HR 5540; 18 G. Apodis) is a solitary star[8] in the constellation Apus. It is faintly visible to the naked eye as an orange-hued point of light with an apparent magnitude of 5.36.[2] Parallax measurements imply a distance of 413 light-years[1] and it is drifting closer with a heliocentric radial velocity of Template:Val.[6] At its current distance, R Apodis' brightness is diminished by an interstellar extinction of 0.26 magnitudes[9] and it has an absolute magnitude of −0.22.[7]
HD 131109 was the first star observed to be variable in the constellation; It was first discovered in 1873 by Benjamin Apthorp Gould. Later, it was hastily given the variable star designation R Apodis in a 1907 variable star catalogue despite it being a suspected variable star at the time.[10] However, observations conducted in a 1952 field star survey revealed that R Apodis was not variable at all.[11] Keenan & Pitts (1980) found that it varied between magnitudes 5.5 and 6.1, but this was never confirmed.[12] Hipparcos photometric data revealed that R Apodis indeed had a constant brightness.[13] It has since been listed as a class CST: in the General Catalog of Variable Stars.[5]
R Apodis has a stellar classification of K4 III:,[3] indicating that it is an evolved K-type giant that has ceased hydrogen fusion at its core and left the main sequence. However, there is uncertainty about the luminosity class. It has a comparable mass to the Sun at 1.1 solar masses but, at the age of 5.68 billion years, it has expanded to 23 times the radius of the Sun.[6] It radiates 293 times the luminosity of the Sun[1] from its enlarged photosphere at an effective temperature of Template:Val.[6] R Apodis is metal deficient with an iron abundance roughly half of the Sun's[6] and it spins slowly with a projected rotational velocity lower than Template:Val.[14]
References
- ↑ a b c d e f g h Cite error: Invalid
<ref>tag; no text was provided for refs namedGaiaDR3 - ↑ a b Cite error: Invalid
<ref>tag; no text was provided for refs namedTycho2000 - ↑ a b Cite error: Invalid
<ref>tag; no text was provided for refs namedperkins - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedCousins1977 - ↑ a b Cite error: Invalid
<ref>tag; no text was provided for refs namedgcvs - ↑ a b c d e f Cite error: Invalid
<ref>tag; no text was provided for refs namedjofre - ↑ a b Cite error: Invalid
<ref>tag; no text was provided for refs namedaaa458_2_609 - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedEggleton2008 - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedGontcharov2017 - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedCannon1907 - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedGaposchkin1952 - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedKeenan1980 - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedPerryman1997 - ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedDe Medeiros2014