Delta Apodis (δ Aps, δ Apodis) is the

Bayer designation A Bayer designation is a stellar designation in which a specific star is identified by a Greek or Latin letter followed by the genitive form of its parent constellation's Latin name. The original list of Bayer designations contained 1,564 stars. ...

for a

double star In observational astronomy, a double star or visual double is a pair of stars that appear close to each other as viewed from Earth, especially with the aid of optical telescopes. This occurs because the pair either forms a binary star (i.e. a bi ...

in the southern

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the e ...

Apus Apus is a small constellation in the Southern Celestial Hemisphere, southern sky. It represents a bird-of-paradise, and its name means "without feet" in Greek language, Greek because the bird-of-paradise was once wrongly believed to lack feet. ...

The brighter star, δ Apodis, is an M-type

red giant A red giant is a luminous giant star of low or intermediate mass (roughly 0.3–8 solar masses ()) in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius large and the surface temperature around or ...

and has an

apparent magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's li ...

that varies from magnitude +4.66 to +4.87. It is classified as a semiregular variable with pulsations of multiple periods of 68.0, 94.9 and 101.7 days. At an

angular separation Angular distance \theta (also known as angular separation, apparent distance, or apparent separation) is the angle between the two sightlines, or between two point objects as viewed from an observer. Angular distance appears in mathematics (in pa ...

of 102.9

arcsecond A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of one degree. Since one degree is of a turn (or complete rotation), one minute of arc is of a turn. The na ...

s is δ Apodis, an orange K-type giant with an

of +5.27.

Hipparcos ''Hipparcos'' was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993. It was the first space experiment devoted to precision astrometry, the accurate measurement of the positions of celestial obj ...

data report the distance to δ Apodis to be approximately 760 light years, while δ Apodis is found to be around 610 light years from

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

. They may form a

common proper motion This glossary of astronomy is a list of definitions of terms and concepts relevant to astronomy and cosmology, their sub-disciplines, and related fields. Astronomy is concerned with the study of celestial objects and phenomena that originate outsid ...

pair.

Naming

Chinese Chinese can refer to: * Something related to China * Chinese people, people of Chinese nationality, citizenship, and/or ethnicity **''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation ** List of ethnic groups in China, people of va ...

caused by adaptation of the European southern hemisphere constellations into the Chinese system, (), 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 (, en, the Sixth Star of Exotic Bird.)AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 29 日
/ref>

References

External links

Image δ Apodis
{{DEFAULTSORT:Delta Apodis 145366 Apodis, Delta Apus (constellation) Double stars Semiregular variable stars K-type giants M-type giants 080047 57 6020 Durchmusterung objects