Delta Apodis
 Location of δ Apodis (circled) |
|
| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Apus |
| δ1 Aps | |
| Right ascension | 16h 20m 20.80462s[1] |
| Declination | –78° 41′ 44.6889″[1] |
| Apparent magnitude (V) | +4.76[2] |
| δ2 Aps | |
| Right ascension | 16h 20m 26.85843s[1] |
| Declination | –78° 40′ 02.9901″[1] |
| Apparent magnitude (V) | +5.27[2] |
| Characteristics | |
| Spectral type | M5 IIIb + K3 III[3] |
| U−B color index | +1.68/+1.62[2] |
| B−V color index | +1.69/+1.41[2] |
| Variable type | irregular variable |
| Astrometry | |
| δ1 Aps | |
| Radial velocity (Rv) | –12.0[4] km/s |
| Proper motion (μ) | RA: –10.23[1] mas/yr Dec.: –37.43[1] mas/yr |
| Parallax (π) | 4.28 ± 0.16[1] mas |
| Distance | 760 ± 30 ly (234 ± 9 pc) |
| δ2 Aps | |
| Radial velocity (Rv) | –10.2[5] km/s |
| Proper motion (μ) | RA: –1.75[1] mas/yr Dec.: –31.58[1] mas/yr |
| Parallax (π) | 5.32 ± 0.22[1] mas |
| Distance | 610 ± 30 ly (188 ± 8 pc) |
| Other designations | |
| δ1 Aps: HD 145366, HIP 80047, SAO 257380.[6] | |
| δ2 Aps: HD 145388, HIP 80057, SAO 257381.[7] | |
Delta Apodis (δ Aps, δ Apodis) is the Bayer designation for a double star in the southern constellation of Apus.
The brighter star, δ¹ Apodis, is a M-type red giant with a mean apparent magnitude of +4.68. It is classified as an irregular variable[8] star and its brightness varies from magnitude +4.66 to +4.87. At an angular separation of 102.9 arcseconds is δ² Apodis, an orange K-type giant with an apparent magnitude of +5.27.
Hipparcos data report the distance to δ¹ Apodis to be approximately 760 light years, while δ² Apodis is found to be around 610 light years from Earth. They may form a common proper motion pair.
Naming
In Chinese caused by adaptation of the European southern hemisphere constellations into the Chinese system, 異雀 (Yì Què), meaning Exotic Bird, refers to an asterism consisting of δ1 Apodis, ζ Apodis, ι Apodis, β Apodis, γ Apodis, δ Octantis, η Apodis, α Apodis and ε Apodis. Consequently, δ1 Apodis itself is known as 異雀六 (Yì Què liù, English: the Sixth Star of Exotic Bird.)[9]
References
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- ↑ 2.0 2.1 2.2 2.3 Lua error in package.lua at line 80: module 'strict' not found.
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- ↑ 7.0 7.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 29 日
