Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Aquila |
Right ascension | 19h 50m 17.47943s |
Declination | +07° 54′ 08.6934″ |
Apparent magnitude (V) | 6.484 |
Characteristics | |
Spectral type | B2.5IVe |
U−B color index | -0.7 |
B−V color index | -0.1 |
Variable type | Be star |
Astrometry | |
Radial velocity (Rv) | -30.10 ± 5 km/s |
Proper motion (μ) | RA: -0.77 ± 0.39 mas/yr Dec.: -5.44 ± 0.46 mas/yr |
Parallax (π) | 1.89 ± 0.45 mas |
Distance | approx. 1,700 ly (approx. 500 pc) |
Details | |
Mass | 13.0 [2] M☉ |
Radius | 7.7 [2] R☉ |
Temperature | 23310 [2] K |
Other designations | |
Database references | |
SIMBAD | data |
V1339 Aquilae, also known as HD 187567, is a Be star in the constellation Aquila. At its brightest its apparent magnitude is 6.22, [3] making it barely visible to the naked eye at a location with very little light pollution. It is located just 8 arc seconds from the center of the open cluster NGC 6828. [4]
V1339 Aquilae was discovered to be a Be star in 1925 by P. W. Merrill, M. L. Humason and C. G. Burwell. [5] The star's variability was detected in 1966 by A. W. J. Cousins, R. Lake and R. H. Stoy, [6] and because of this it was given its variable star designation, V1339 Aquilae, in 1979. [7]
V1339 Aquilae is around 13 times as massive as the Sun and has 7.7 times its diameter. [2] Its binary nature was discovered by speckle interferometry in 1983, at the Kitt Peak 4 meter telescope. At the time of these speckle observations the stars were separated by 0.057 arc seconds. [8]
Albireo is a double star designated Beta Cygni. The International Astronomical Union uses the name "Albireo" specifically for the brightest star in the system. Although designated 'beta', it is fainter than Gamma Cygni, Delta Cygni, and Epsilon Cygni and is the fifth-brightest point of light in the constellation of Cygnus. Appearing to the naked eye to be a single star of magnitude 3, viewing through even a low-magnification telescope resolves it into its two components. The brighter yellow star, itself a very close binary system, makes a striking colour contrast with its fainter blue companion.
Delta Scuti, Latinized from δ Scuti, is a variable star in the southern constellation Scutum. With an apparent visual magnitude that fluctuates around 4.72, it is the fifth-brightest star in this small and otherwise undistinguished constellation. Analysis of the parallax measurements place this star at a distance of about 199 light-years from Earth. It is drifting closer with a radial velocity of −45 km/s.
Theta Andromedae is a binary star system in the northern constellation of Andromeda. Theta Andromedae, Latinized from θ Andromedae, is its Bayer designation. It is located at a distance of approximately 173 light-years from the Sun, and has an apparent visual magnitude of 4.6. On the Bortle Dark-Sky Scale, this makes it visible to the naked eye from outside urban regions. Based on its motion through space, this system appears to be a member of the Sirius supercluster.
Sigma Aquilae, Latinized from σ Aquilae, is the Bayer designation for a binary star system in the equatorial constellation of Aquila. The baseline apparent magnitude of the pair is +5.17, which, according to the Bortle Dark-Sky Scale, is bright enough to be seen with the naked eye from suburban skies. Because of the Earth's orbit about the Sun, this system has an annual parallax shift of 4.18 mas. This provides a distance estimate of approximately 780 light-years.
Chi Aquilae is the Bayer designation for a binary star in the equatorial constellation of Aquila, the eagle. This system is bright enough to be seen with the naked eye at a combined visual magnitude of +5.29. Based upon parallax measurements made during the Hipparcos mission, Chi Aquilae is at a distance of approximately 900 light-years from Earth.
18 Aquilae is a triple star system in the constellation of Aquila. 18 Aquilae is the Flamsteed designation; it also bears the variable star designation Y Aquilae. It has an apparent visual magnitude of 5.07. The distance to this system can be estimated from the annual parallax shift of 6.43 mas, yielding a value of around 510 light-years away from Earth.
21 Aquilae is a solitary variable star in the equatorial constellation of Aquila. It has the variable star designation V1288 Aql; 21 Aquilae is its Flamsteed designation. This object is visible to the naked eye as a dim, blue-white hued star with a baseline apparent visual magnitude of about 5.1. The star is located at a distance of around 680 light-years from Earth, give or take a 20 light-year margin of error. It is moving closer to the Earth with a heliocentric radial velocity of –5 km/s.
51 Aquilae is a star in the equatorial constellation of Aquila. 51 Aquilae is its Flamsteed designation. It has an apparent visual magnitude of 5.39, which means it is faintly visible to the naked eye. Based upon an annual parallax shift of 35.88 mas, the distance to this star is around 90.9 light-years.
28 Aquilae, abbreviated 28 Aql, is a star in the equatorial constellation of Aquila. 28 Aquilae is its Flamsteed designation though it also bears the Bayer designation A Aquilae, and the variable star designation V1208 Aquilae. It has an apparent visual magnitude is 5.5, making this a faint star that requires dark suburban skies to view. The annual parallax shift of 9.6 mas means this star is located at a distance of approximately 340 light-years from Earth.
35 Aquilae is a star in the equatorial constellation of Aquila. 35 Aquilae is its Flamsteed designation though it also bears the Bayer designation c Aquilae. The apparent visual magnitude of this star is 5.8, which means it is a faint star but visible to the naked eye from dark suburban or rural skies. It has an annual parallax shift of 16.34 mas that is caused by the Earth's orbit around the Sun. This yields a distance estimate of 200 light-years, give or take a 4 light-year margin of error. At this distance, the visual magnitude is diminished by 0.26 from extinction caused by interstellar gas and dust.
10 Aquilae is a star in the equatorial constellation of Aquila. 10 Aquilae is the Flamsteed designation. It has an apparent visual magnitude of 5.9 and thus is a faint star that is just visible to the naked eye in dark skies. The brightness of this star is diminished by 0.17 in visual magnitude from extinction caused by interstellar gas and dust. Based on an annual parallax shift of 13.45 mas, the distance to this star is around 240 light-years.
V Aquilae is a carbon star and semiregular variable star in the constellation Aquila. It has an apparent magnitude which varies between 6.6 and 8.4 and is located around 400 parsecs (1,300 ly) away.
FF Aquilae is a classical Cepheid variable star located in the constellation Aquila, close to the border with Hercules. It ranges from apparent magnitude 5.18 to 5.51 over a period of 4.47 days, meaning it is faintly visible to the unaided eye in rural or suburban settings.
HD 1185 is a double star in the northern constellation of Andromeda. The primary, with an apparent magnitude of 6.15, is a white main-sequence star of spectral type A2VpSi, indicating it has stronger silicon absorption lines than usual, thus making it also an Ap star. The secondary companion, which is 9.08 arcseconds away, is not visible to the naked eye at an apparent magnitude of 9.76. It shares common proper motion and parallax with the primary star but orbital parameters are still unknown.
HD 155035 is a star in the constellation Ara, the Altar. It is located at a distance of approximately 1,450 light-years from Earth and has an apparent visual magnitude of 5.92, making it is faintly visible to the naked eye. This is a red giant star with a stellar classification of M1.5 III. It an irregular variable that changes brightness over an amplitude range of 0.12 magnitudes.
Beta Monocerotis is a triple star system in the constellation of Monoceros. To the naked eye, it appears as a single star with an apparent visual magnitude of approximately 3.74, making it the brightest visible star in the constellation. A telescope shows a curved line of three pale blue stars. William Herschel who discovered it in 1781 commented that it is "one of the most beautiful sights in the heavens". The star system consists of three Be stars, β Monocerotis A, β Monocerotis B, and β Monocerotis C. There is also an additional visual companion star that is probably not physically close to the other three stars.
Chi2 Orionis is a B-type blue supergiant star in the constellation of Orion. It has an apparent visual magnitude of 4.63 but being quite distant, and heavily extinguished it burns with the greatest absolute visual light magnitude among stars in Orion within the near reaches of the galaxy, 0.9 of a magnitude brighter than Rigel. Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified. It is considered to be a member of the Gemini OB1 association.
9 Cephei, also known as V337 Cephei, is a variable star in the constellation Cepheus.
HD 183143 is a blue hypergiant star located in the constellation of Sagitta.
WZ Columbae, also known as HD 38170, is a solitary, bluish-white hued star located in the southern constellation Columba, the dove. It has an apparent magnitude of 5.28, allowing it to be faintly visible to the naked eye. Based on parallax measurements from the Gaia spacecraft, the object is about 365 light years distant. It appears to be receding from the Solar System, having a heliocentric radial velocity of 36.3 km/s.