Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Ara |
Right ascension | 16h 56m 08.8405s [1] |
Declination | –50° 40′ 29.244″ [1] |
Apparent magnitude (V) | 6.275 [2] |
Characteristics | |
Spectral type | B3 Vnpe |
U−B color index | –0.691 [2] |
B−V color index | +0.008 [2] |
Astrometry | |
Radial velocity (Rv) | +19 [3] km/s |
Proper motion (μ) | RA: –7.66 [1] mas/yr Dec.: –9.79 [1] mas/yr |
Parallax (π) | 5.06 ± 0.39 mas [1] |
Distance | 640 ± 50 ly (200 ± 20 pc) |
Absolute magnitude (MV) | −0.16 [4] |
Orbit [5] | |
Period (P) | 236.50 ± 0.18 d |
Inclination (i) | 60 ± 7° |
Periastron epoch (T) | HJD 2458672.10 ± 0.72 |
Semi-amplitude (K1) (primary) | 4.33 ± 0.05 km/s |
Semi-amplitude (K2) (secondary) | 52.83 ± 1.49 km/s |
Details | |
ρ1 Ara A | |
Mass | 6.5 ± 1.3 [5] M☉ |
Radius | 4.21 ± 0.20 [6] R☉ |
Luminosity | 1,418 [7] L☉ |
Surface gravity (log g) | 3.75 [8] cgs |
Temperature | 19,800 [8] K |
Rotational velocity (v sin i) | 370 ± 10 [9] km/s |
Age | 18.4 ± 1.5 [10] Myr |
ρ1 Ara B | |
Mass | 0.53 ± 0.11 [5] M☉ |
Radius | 0.27 ± 0.04 [6] R☉ |
Luminosity | 204 [6] L☉ |
Temperature | 42,000 [6] K |
Other designations | |
Database references | |
SIMBAD | data |
Rho1 Arae is the Bayer designation for a star in the southern constellation of Ara. Unusually for a star with a Bayer designation, it was not catalogued by Bayer in his Uranometria . It was instead first catalogued by Nicolas Lacaille, in his Coelum Australe Stelliferum published in 1763. This star gained the Bayer designation of Rho1 Arae in Bode's Uranographia , published in 1801. Rho1 Arae is one of the dimmest stars with a Bayer designation, having an apparent visual magnitude of just +6.275 [2] According to the Bortle Dark-Sky Scale, this means the star is just barely visible to the naked eye in dark rural skies. Based upon parallax measurements, it is about 640 light-years (200 parsecs ) distant from the Sun, give or take a 50-light-year margin of error. [1]
The Hipparcos data revealed that Rho1 Arae is a variable star. It was given its variable star designation, V846 Arae, in 1999. [13] This is a spectroscopic binary system, which means that the presence of an orbiting companion is indicated by shifts in the spectrum. The primary star is a Be star, while the secondary star is a subdwarf O star; they orbit each other with a period of about 236.50 days. [5] The combined spectrum of this system matches a stellar classification of B3 Vnpe, which may indicate the primary is a B-type main-sequence star. The 'e' suffix indicates the presence of emission lines from the primary Be star. For Rho1 Arae, the emission lines are prominent and variable. [9] The primary star is spinning rapidly with a projected rotational velocity of 370 ± 10, which makes it difficult to obtain reliable orbital elements. [9]
Rho1 Arae has a peculiar velocity of 27.4 ± 4.9 km/s relative to its neighbors, [10] making it a runaway star system. A scenario that it was ejected from the Scorpius–Centaurus OB association as a result of a past supernova explosion seems unlikely because of its binarity. [9]
Epsilon Apodis, Latinized from ε Apodis, is the Bayer designation for a star in the southern circumpolar constellation of Apus. It has an apparent visual magnitude of 5.06, which is bright enough to be viewed from dark suburban skies. Based upon parallax measurements, it is at a distance of roughly 640 light-years from Earth.
Beta Arae, is the brightest star in the constellation of Ara. It is a very luminous, relatively young supergiant star with an apparent magnitude of 2.84 and an absolute magnitude of -3.494. It is located about 713 light-years from Earth. At this distance, its apparent magnitude is diminished by 0.193 magnitudes due to interstellar extinction between Earth and the star.
Gamma Arae is a star in the southern constellation of Ara. With an apparent visual magnitude of 3.3, it is the fourth-brightest star in the constellation and is readily visible to the naked eye. From parallax measurements made during the Hipparcos mission, the distance to this star can be estimated as 1,110 light-years from Earth.
Iota Arae, Latinized from ι Arae, is the Bayer designation for a star in the southern constellation of Ara. It is 920 light-years from Earth, give or take a 20 light-year margin of error, and has an apparent visual magnitude of 5.2. Based upon the Bortle Dark-Sky Scale, this means the star is visible to the naked eye from suburban skies.
V539 Arae (Bayer designation Nu1 Arae (ν1 Arae / ν1 Ara)) is a triple star system in the southern constellation of Ara. It is a variable star, the brightness of which varies from magnitude 5.71 to 6.24, making it faintly visible to the naked eye under good observing conditions. Based upon an annual parallax shift of 3.30 ± 0.47, this system is at a distance of roughly 1,000 light-years (310 parsecs) from Earth.
3 Centauri is a triple star system in the southern constellation of Centaurus, located approximately 300 light years from the Sun. It is visible to the naked eye as a faint, blue-white hued star with a combined apparent visual magnitude of 4.32. As of 2017, the two visible components had an angular separation of 7.851″ along a position angle of 106°. The system has the Bayer designation k Centauri; 3 Centauri is the Flamsteed designation. It was a suspected eclipsing binary with a variable star designation V983 Centauri, however the AAVSO website lists it as non-variable, formerly suspected to be variable.
RV Caeli, also known as HD 28552, is a solitary, red hued variable star located in the southern constellation Caelum, the chisel. It has an apparent magnitude of 6.4, placing it near the limit for naked eye visibility. The object is located relatively far at a distance of 1,340 light years based on parallax measurements from Gaia DR3, but is rapidly receding with a heliocentric radial velocity of 98 km/s.
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.
HD 158220 is a giant Be star in the southern constellation of Ara. Its apparent magnitude is 5.9, makeing it faintly visible to the naked eye under good observing conditions. This is a pulsating variable star that changes brightness by an amplitude of 0.030 magnitude over a period of 1.15 days.
HD 160342 is a star in the southern constellation of Ara. HD 160342 is its Henry Draper Catalogue designation. It has an apparent visual magnitude of 6.35, making it very faintly visible to the naked eye under ideal observing conditions. Based upon parallax measurements, is approximately 960 light-years distant from Earth.
Kappa1 Apodis, Latinized from κ1 Apodis, is a binary star system in the southern circumpolar constellation of Apus. Based upon parallax measurements, it is located roughly 1,060 light-years from Earth. The combined apparent visual magnitude of the system is 5.52, indicating that this is a faint, naked eye star that can be viewed in dark suburban skies. It is moving away from the Sun with a radial velocity of +62 km/s.
CQ Camelopardalis, abbreviated as CQ Cam, is a solitary variable star in the northern circumpolar constellation Camelopardalis. It has an apparent magnitude of 5.19, making it visible to the naked eye under ideal conditions. The object is relatively far at a distance of about 2,000 light years but is drifting closer with a heliocentric radial velocity of −22 km/s. It has a peculiar velocity of 21.8+2.1
−1.9 km/s, making it a runaway star.
13 Scorpii, also known by its Bayer designation c2 Scorpii, is a binary star in the constellation Scorpius. Its apparent magnitude is 4.57, meaning it can be faintly seen with the naked eye. Based on parallax estimates made by the Hipparcos spacecraft, the system is located about 480 light-years away. It is located within the Upper Scorpius subgroup of the Scorpius–Centaurus association.
47 Cygni is a triple star system in the northern constellation of Cygnus, and is located around 4,000 light years from the Earth. It is visible to the naked eye with a combined apparent visual magnitude of 4.61. The system is moving closer to the Earth with a heliocentric radial velocity of −4.6 km/s.
28 Cygni is a binary star in the northern constellation of Cygnus. It is a faint blue-white hued star but visible to the naked eye with an apparent visual magnitude of 4.93. The distance to 28 Cyg, as estimated from its annual parallax shift of 5.3 mas, is around 620 light years. It has an absolute magnitude of −2.56, which means that if the star were just 10 parsecs away it would be brighter than Sirius, the brightest star in the night sky.
5 Lacertae is a spectroscopic binary in the constellation Lacerta. Its apparent magnitude is 4.36.
48 Persei is a Be star in the constellation Perseus, approximately the 500th brightest of the visible stars in apparent magnitude. It is "well known for its complex spectrum and for its light and velocity variations". The name "48 Persei" is a Flamsteed designation given to it by John Flamsteed in his catalogue, published in 1712.
V1073 Scorpii is a variable star in the constellation Scorpius. It has a non-Greek Bayer designation of k Scorpii. The star has a blue-white hue and is visible to the naked eye with an apparent visual magnitude that fluctuates around +4.87. Parallax measurements yield a distance estimate of approximately 2,920 ly (896 pc) from the Sun, and it is drifting further away with a radial velocity of +7 km/s. It has an absolute magnitude of −6.8
HD 34989 is a blue-white star in the main sequence, of apparent magnitude 5.80, in the constellation of Orion. It is 1700 light-years from the Solar System.
MZ Puppis is a red supergiant star in the constellation of Puppis. It has a radius of 400 R☉ and a mass of 14 solar masses, similar to Betelgeuse.
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