This is a list of O-type stars by their distance from Earth. [1] [2] [3]
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Star system ← ← | Median distance (ly) | Stars in system | Spectral type | Apparent magnitude (V) | Comments and references |
---|---|---|---|---|---|
Zeta Ophiuchi | 440 ± 40 | 1 | O9.5 V | 2.56 – 2.58 | The closest O-type star to Earth. |
Zeta Puppis (Naos) | 1,080 ± 40 | 1 | O4If(n)p | 2.24 - 2.26 | |
Gamma² Velorum (Suhail al Muhlif/Regor) | 1096+26 −23 | 2 | O7.5III | 1.83 | Has a Wolf-Rayet Companion. |
Mintaka A (Delta Orionis, 34 Orionis) | 1,200 | 3 | O9.5II | 2.5 | |
Alnitak (Zeta Orionis, 50 Orionis) | 1,260 ± 180 | 3 | O9.5Iab | 1.77 | |
Sigma Orionis A | 1263±4.3 | 2 | O9.5V | 4.07 | |
Meissa A (Lambda Orionis) | 1260±200 | 1 | O8 III((f)) | 3.7 | |
AE Aurigae | 1,320 ± 40 | 1 | O9.5V | 5.96 | |
Xi Persei (Menkib) | 1340±65 | 1 | O7.5III(n)((f)) | 4.04 | |
Theta¹ Orionis C1 | 1340±65 | 1 | O6Vp | 5.13 | |
Iota Orionis (Haytsa) | 1343+45.6 −42.3 | 3 | O9 III | 2.77 | |
10 Lacertae | 1,800±103 | 1 | O9V | 4.880 | |
Mu Columbae | 1,894±111 | 1 | O9.5 V | 5.18 | |
HD 186924 | 2000 | 1 | O6fp | It is the central star of NGC 6826 Planetary Nebula. | |
HD 49798 | 2120.02 | 1 | sdO6p | 8.287 | |
Delta Circini | 2,300 ± 200 | 1 | O7.5III(f) | 5.09 | |
S Monocerotis (15 Monocerotis) | 2,300 ± 200 | 3 | O7V((f))zvar[4] + O9.5Vn | ||
Lambda Cephei | 3098.5 | 1 | O6.5If(n)p | +5.050 | |
Mu Normae | 3,260 | 1 | O9.7Iab | 4.91 | |
HD 35914 | 3,600 | 1 | O7fp | It is the central star of IC 418 Planetary Nebula. | |
UW Canis Majoris | 3,800 | 2 | O7.5-8Iabf + O9.7Ib | 4.95 | |
19 Cephei | 3,913.88 | 1 | O9Ib | 5.08 | |
HD 54879 | 4100 ± 200 | 1 | O9.7V | 7.65 | |
HD 164492 A | 4100 ± 200 | 1 | O7.5III | ||
9 Sagittarii | 4,100 ± 400 | 1 | O4V((f))z | 5.97 | |
15 Sagittarii | 4,200±650 | 1 | O9.7 Iab | 5.37 | |
HD 149404 (V918 Scorpii) | 4,300 ± 400 | 2 | O7.5I(f) + ON9.7I | 5.42 - 5.50 | |
Tau Canis Majoris | 5,120.66 | 3 | O9II | 4.40 | |
4U 1700-37 (V884 Scorpii) | 5,200 ± 200 | 1 | O6Iafcp | 6.51 | |
Plaskett's Star (V640 Monocerotis) | 5,245 | 2 | O8I + O7.5III | 6.06 | |
Cygnus OB2-8A | 5,400 ± 200 | 1 | O6If + O5.5III(f) | 9.06 | |
BD+43 3654 | 5,400 ± 300 | 1 | O4If | 10.06 | |
Alpha Camelopardalis | 6,000 | 1 | O9Ia | 4.29 | |
WR 133 (V1676 Cyg) | 6,100 ± 300 | 2 | O9I | 6.75 - 6.84 | Has a Wolf-Rayet Companion. |
HD 59088 | 6,500 | 1 | O(H)6f | It is the central star of NGC 2392 Planetary Nebula. | |
WR 25 (HD 93162) | 6,500 | 2 | O2.5If*/WN6 + OB | 8.80 | |
Pismis 24-1 (HD 319718) | 6,500 | 2 | O3.5If*+O4III(f+) | ||
HD 151804 (V973 Scorpii) | 7,000 | 1 | O8 Iaf | 5.22 - 5.28 | |
HD 138403 | 7175.44 | 1 | O8(f)ep | It is the central star of Hen 2-131 Planetary Nebula. | |
Cygnus X-1 | 7,300 ± 200 | 2 | O9.7Iab | 8.95 | |
Theta Muscae | 7,400 | 4 | O6/7V + O9.5/B0Iab+O9III | 5.53 | Has a Wolf-Rayet Companion. |
Eta Carinae (Eta Argus) | 7,500 | 2 | O | −1.0 to ~7.6 | part of Trumpler 16 in the Carina Nebula. |
HD 93129 | 7,501.6 | 1 | O2If*+O3.5 V((f))z | 6.90 | |
QZ Carinae (HD 93206) | 7,501.6 | 4 | O9.7I+O8III+O9V | 6.24 | |
HD 93205 (V560 Carinae) | 7,600 ± 400 | 2 | O3.5Vf + O8V | 7.75 | |
LSS 4067 (CD−38°11748) | 9,500–12,700 | 1 | O4.5Ifpe | 11.44 | |
BD+60°2522 | 9,800 ± 400 | 1 | O6.5(f)(n)p | 8.67 | |
HD 93403 | 10,000 | 1 | O5.5III(fc)var | 7.272 | |
WR 20a | 14,000 ± 1,000 | 2 | O3If*/WN6 + O3If*/WN6 | 13.28 | |
GCIRS 16SW | 20,000 | 1 | Ofpe/WN9 | ||
GCIRS 8* | 20,000 | 1 | O5 | ||
V1936 Aquilae | 20,000 | 1 | O4I | 15.1 | |
Westerhout 51-57 | 20,000 | 1 | O4V | Member of Westerhout 51. | |
MTT 68 | 24,787.88 | 1 | O2If* | 14.72 | |
WR 42e (2MASS J11144550-115001) | 25,000 | 1 | O3If*/WN6 | 14.53 | |
WR 102ka (Peony star) | 26,000 | 2 | Ofpe/WN9 | ||
Westerhout 49-2 | 36,200 | 1 | O2-3.5If* | ||
The Large Magellanic Cloud (LMC) is around 163 kly distant and the Small Magellanic Cloud (SMC) is around 204 kly distant
Host galaxy | Star system | Median distance (ly) | Stars in system | Spectral type | Apparent magnitude (V) | Comments and references |
---|---|---|---|---|---|---|
LMC | R136b | 163,000 | 1 | O4If | 13.24 | |
LMC | LH 54-425 | 163,000 | 2 | O3V + O5V | 13.13 | |
LMC | HD 269810 | 163,000 | 1 | O2III(f*) | 12.22 | |
LMC | Melnick 42 | 163,000 | 1 | O2If* | 12.78 | |
LMC | BI 253 | 164,000 | 1 | O2V-III(n)((f*)) | 13.76 | |
LMC | VFTS 243 (2MASS J05380840-6909190) | 164,000 | 1 | O7V(n)((f)) | 15.26 | Has a Known Black Hole Companion |
LMC | VFTS 102 | 164,000 | 1 | O9:Vnnne | 15.806 | |
LMC | HD 97950 | 164,000 | 1 | O | ||
SMC | SMC AB7 | 197,000 | 2 | O6I(f) | 13.016 | |
SMC | SMC AB8 | 197,000 | 2 | O4V | 12.83 | |
SMC | HD 5980 | 200,000 | 3 | LBV + WN4 + OI | 8.8 - 11.9 | |
The Andromeda Galaxy (M31) is 2.5 Mly distant and the Triangulum Galaxy is around 3.2 Mly distant
Host galaxy | Star system | Median distance (ly) | Stars in system | Spectral type | Apparent magnitude (V) | Comments and references |
---|---|---|---|---|---|---|
Triangulum | [BMS2003] 867 | 2,700,000 | 2 | O4Iab+O4Ia | ||
Triangulum | M33-013406.63 (B416/UIT301) | 3,000,000 | 1 | O9.5Ia | ||
Host Galaxy | Star system | Median distance (ly) | Stars in system | Spectral type | Apparent magnitude (V) | Comments and references |
---|---|---|---|---|---|---|
IC 3418 | SDSS J1229+1122 | 550,000,000 | 1 | O | 22.85 | |
Tucana is a constellation in the southern sky, named after the toucan, a South American bird. It is one of twelve constellations conceived in the late sixteenth century by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman. Tucana first appeared on a 35-centimetre-diameter (14 in) celestial globe published in 1598 in Amsterdam by Plancius and Jodocus Hondius and was depicted in Johann Bayer's star atlas Uranometria of 1603. French explorer and astronomer Nicolas Louis de Lacaille gave its stars Bayer designations in 1756. The constellations Tucana, Grus, Phoenix and Pavo are collectively known as the "Southern Birds".
The Large Magellanic Cloud (LMC) is a dwarf galaxy and satellite galaxy of the Milky Way. At a distance of around 50 kiloparsecs (163,000 light-years), the LMC is the second- or third-closest galaxy to the Milky Way, after the Sagittarius Dwarf Spheroidal (c. 16 kiloparsecs (52,000 light-years) away) and the possible dwarf irregular galaxy called the Canis Major Overdensity. Based on the D25 isophote at the B-band (445 nm wavelength of light), the Large Magellanic Cloud is about 9.86 kiloparsecs (32,200 light-years) across. It is roughly one-hundredth the mass of the Milky Way and is the fourth-largest galaxy in the Local Group, after the Andromeda Galaxy (M31), the Milky Way, and the Triangulum Galaxy (M33).
Crater is a small constellation in the southern celestial hemisphere. Its name is the latinization of the Greek krater, a type of cup used to water down wine. One of the 48 constellations listed by the second-century astronomer Ptolemy, it depicts a cup that has been associated with the god Apollo and is perched on the back of Hydra the water snake.
Wolf–Rayet stars, often abbreviated as WR stars, are a rare heterogeneous set of stars with unusual spectra showing prominent broad emission lines of ionised helium and highly ionised nitrogen or carbon. The spectra indicate very high surface enhancement of heavy elements, depletion of hydrogen, and strong stellar winds. The surface temperatures of known Wolf–Rayet stars range from 20,000 K to around 210,000 K, hotter than almost all other kinds of stars. They were previously called W-type stars referring to their spectral classification.
S Doradus is one of the brightest stars in the Large Magellanic Cloud (LMC), a satellite galaxy of the Milky Way, located roughly 160,000 light-years away. The star is a luminous blue variable, and one of the most luminous stars known, having a luminosity varying widely above and below 1,000,000 times the luminosity of the Sun, although it is too far away to be seen with the naked eye.
Messier 2 or M2 is a globular cluster in the constellation Aquarius, five degrees north of the star Beta Aquarii. It was discovered by Jean-Dominique Maraldi in 1746, and is one of the largest known globular clusters.
An O-type main-sequence star is a main-sequence star of spectral type O and luminosity class V. These stars have between 15 and 90 times the mass of the Sun and surface temperatures between 30,000 and 50,000 K. They are between 40,000 and 1,000,000 times as luminous as the Sun.
HD 269810 is a blue giant star in the Large Magellanic Cloud. It is one of the most massive and most luminous stars known, and one of only a handful of stars with the spectral type O2. The star's name, HD 269810, comes from the Henry Draper Catalogue. The serial number 269810 indicates it was published in the extension of the catalogue and is formally referred to as HDE 269810.
In astronomy, stellar kinematics is the observational study or measurement of the kinematics or motions of stars through space.
Mensa is a constellation in the Southern Celestial Hemisphere near the south celestial pole, one of fourteen constellations drawn up in the 18th century by French astronomer Nicolas-Louis de Lacaille. Its name is Latin for table, though it originally commemorated Table Mountain and was known as "Mons Mensae". One of the eighty-eight constellations designated by the International Astronomical Union (IAU), it covers a keystone-shaped wedge of sky 153.5 square degrees in area. Other than the south polar constellation of Octans, it is the most southerly of constellations and is observable only south of the 5th parallel of the Northern Hemisphere.
HD 5980 is a multiple star system on the outskirts of NGC 346 in the Small Magellanic Cloud (SMC) and is one of the brightest stars in the SMC.
AB7, also known as SMC WR7, is a binary star in the Small Magellanic Cloud. A Wolf–Rayet star and a supergiant companion of spectral type O orbit in a period of 19.56 days. The system is surrounded by a ring-shaped nebula known as a bubble nebula.
Classical Cepheids are a type of Cepheid variable star. They are young, population I variable stars that exhibit regular radial pulsations with periods of a few days to a few weeks and visual amplitudes ranging from a few tenths of a magnitude up to about 2 magnitudes. Classical Cepheids are also known as Population I Cepheids, Type I Cepheids, and Delta Cepheid variables.
HV 2112 is a cool luminous variable star in the Small Magellanic Cloud. Until 2018, it was considered to be the most likely candidate for a Thorne–Żytkow object, but it is now thought to be an asymptotic giant branch star.
WR 142 is a Wolf-Rayet star in the constellation Cygnus, an extremely rare star on the WO oxygen sequence. It is a luminous and very hot star, highly evolved and close to exploding as a supernova. It is suspected to be a binary star with a companion orbiting about 1 AU away.
R Sagittae is an RV Tauri variable star in the constellation Sagitta that varies from magnitude 8.0 to 10.5 in 70.77 days. It is a post-AGB low mass yellow supergiant that varies between spectral types G0Ib and G8Ib as it pulsates. Its variable star designation of "R" indicates that it was the first star discovered to be variable in the constellation. It was discovered in 1859 by Joseph Baxendell, though classified as a semi regular variable until RV Tauri variables were identified as a distinct class in 1905.
HV 11423 is a red supergiant star in the Small Magellanic Cloud. It is about 200,000 light-years away towards the constellation of Tucana.
HD 37836 is a candidate luminous blue variable located in the Large Magellanic Cloud and one of the brightest stars in its galaxy.