This is a list of supernova candidates, or stars that are believed to soon become supernovae. Type II supernova progenitors include stars with at least 8~10 solar masses that are in the final stages of their evolution. Prominent examples of stars in this mass range include Antares, Spica, [1] Gamma Velorum, [2] Mu Cephei, and members of the Quintuplet Cluster. [3] Type Ia supernova progenitors are white dwarf stars that are close to the Chandrasekhar limit of about 1.44 solar masses and are accreting matter from a binary companion star.
The list includes massive Wolf–Rayet stars, which may become Type Ib/Ic supernovae, particularly oxygen-sequence (Wolf-Rayet WO) stars. As of 2023, most of these candidates are in the Milky Way galaxy, however five oxygen-sequence Wolf-Rayet stars are also known in other galaxies.
Identifier | Epoch J2000 | Constellation | Distance (light-years) | Spectral class | Possible supernova type | Notes | |
---|---|---|---|---|---|---|---|
R. A. | Dec. | ||||||
IK Pegasi | 21h 26m 26.7s | +19° 22′ 32″ | Pegasus | 154.4±1.0 [4] | A8m:/DA | Ia | [5] [6] [7] |
Spica | 13h 25m 11.6s | −11° 09′ 40.8″ | Virgo | 250+14 −13 [8] | B1 | [7] | |
Bellatrix | 05h 25m 07.86s | +06° 20′ 58.9″ | Orion | 250 | B2III [9] -V [10] | [11] | |
Mimosa | 12h 47m 43.3s | -59h 41m 19.6s | Crux | 280 | B0.5III+B2V [12] [13] | [14] | |
Acrux | 12h 26m 35.9s | -63h 05m 56.7s | Crux | 321 [8] | B0.5IV+B1V [15] | [16] | |
Adhara | 06h 58m 37.6s | –28° 58′ 19″ | Canis Major | 430±30 [17] | B2 II | [18] | |
Betelgeuse | 05h 55m 10.3s | +07° 24′ 25″ | Orion | 408 [19] –548+90 −49 [20] | M2Iab | IIP | [1] [21] [7] [22] |
Alpha Lupi | 14h 41m 55.8s | –47° 23′ 17″ | Lupus | 465+12 −11 [8] | B1.5 | II | [23] [7] |
Mirzam | 06h 22m 42.0s | –17° 57′ 21″ | Canis Major | 490±20 [24] | B1 III | [25] | |
Lambda Velorum | 09h 07m 59.8s | −43° 25′ 57.3″ | Vela | 545 ± 10 [8] | K4Ib | Electron capture | [26] |
Antares | 16h 29m 24.5s | –26° 25′ 55″ | Scorpius | 554+113 −80 [8] | M1.5Iab-b | IIP | [27] [7] [22] |
Epsilon Pegasi | 21h 44m 11.2s | 09° 52′ 30″ | Pegasus | 690±20 [8] | K2Ib-II | [22] | |
Pi Puppis | 07h 17m 08.56s | −37° 05′ 50.9″ | Puppis | 810±70 | K3Ib | [22] | |
Rigel | 05h 14m 32.3s | –08° 12′ 06″ | Orion | 863±78 [8] | B8Ia | IIn(pec?) | [28] [7] |
Gamma2 Velorum | 08h 09m 32.0s | −47° 20′ 12″ | Vela | 1120+130 −100 [8] | WC8+O7.5III | Ib/Ic | [29] |
Sigma Canis Majoris | 07h 01m 43.1s | −27° 56′ 05″ | Canis Major | 1120 | K4III | [22] | |
Delta Canis Majoris | 07h 08m 23.5s | −26° 23′ 35.5″ | Canis Major | 1600 | F8Ia | [30] | |
NS Puppis | 08h 11m 21.5s | −39° 37′ 06.8″ | Puppis | 1695 [22] | K4.5Ib | [22] | |
119 Tauri | 05h 32m 12.8s | +18° 35′ 40″ | Taurus | 1790+300 −220 [31] | M2Iab-Ib | [22] [32] | |
3 Ceti | 00h 04m 30.1s | −10° 30′ 34.3″ | Cetus | 2086 [22] | K3Ib | [22] | |
Alpha Leporis | 05h 32m 43.8s | −17° 49′ 20.2″ | Lepus | 2218 [8] | F0Ib [33] | [34] | |
Deneb | 20h 41m 25.9s | +45° 16′ 49″ | Cygnus | 2615 ± 215 [35] | A2la | Ib/Ic | [36] |
T Coronae Borealis | 15h 59m 30.2s | +25° 55′ 13″ | Corona Borealis | 2690+110 −100 [4] | M3III/D | Ia | [37] |
KPD 1930+2752 | 19h 32m 14.9s | +27° 58′ 35″ | Cygnus | 2860+130 −120 [4] | sdB/D | Ia | [38] [39] |
Mu Cephei | 21h 43m 30.5s | +58° 46′ 48″ | Cepheus | 3060+456 −130 [40] | M2Ia | IIn/IIb | [41] |
Rho Cassiopeiae | 23h 54m 23.0s | +57° 29′ 58″ | Cassiopeia | 3440+930 −610 [4] | G2Ia0e | IIL | [42] |
VY Canis Majoris | 07h 22m 58.3s | −25° 46′ 03″ | Canis Major | 3930+420 −350 [43] | M5eIa | II | [21] [44] |
IRAS 17163-3907 | 17h 19m 49.3s | −39° 10′ 37.9″ | Scorpius | 3930+990 −660 [4] | late B/early A | II | [45] |
VV Cephei | 21h 56m 39.1s | +63° 37′ 32″ | Cepheus | 4900 [46] | M2Iab | [47] | |
HD 168625 | 18h 21m 19.5s | −16° 22′ 26″ | Sagittarius | 5250+600 −490 [4] | B6Ia | II | [48] |
NML Cygni | 20h 46m 25.6s | +40° 06′ 59.4″ | Cygnus | 5250+420 −360 [49] | M6I | II | [50] |
WR 142 | 20h 21m 44.34s | +37° 22′ 30.4″ | Cygnus | 5380 | WO2 | Ic, Grb likely | |
IRC +10420 | 19h 26m 48.1s | +11° 21′ 17″ | Aquila | 5600+2200 −1200 [4] | F8Ia+ | IIb | [51] [52] |
RS Ophiuchi | 17h 50m 13.2s | –06° 42′ 28″ | Ophiuchus | 7380+1000 −790 [4] | M2III/D | Ia | [53] [54] |
WR 93b | 17h 32m 03.31s | –35° 04′ 32.7″ | Scorpius | 7470 | WO3 | Ic | |
WR 2 | 01h 05m 23.03s | +60° 25′ 18.9″ | Cassiopeia | 7830 | WN2-w | Ib/Ic, Grb likely | |
WR 102 | 17h 45m 47.54s | –26° 10′ 26.8″ | Sagittarius | 8610 | WO2 | Ic | |
Eta Carinae | 10h 45m 03.6s | −59° 41′ 04″ | Carina | 8630+69 −68 [4] | LBV/O | Ib, SLSN likely | [55] [56] |
HD 179821 | 19h 13m 58.6s | +00° 07′ 32″ | Aquila | 10500+2100 −1500 [4] | G5Ia | IIL | [57] [58] |
T Pyxidis | 09h 04m 41.5s | −32° 22′ 48″ | Pyxis | 10700+1700 −1300 [4] | Ia | [59] [60] | |
WR 104 | 18h 02m 04.1s | –23° 37′ 41″ | Sagittarius | 13400+9200 −3900 [4] | WC9d/OB | Ib/Ic with Grb? | [61] [62] |
V445 Puppis | 07h 37m 56.9s | –25° 56′ 59″ | Puppis | 16000+5200 −4600 [63] | Ia | [64] | |
WR 38 | 11h 05m 46.43s | −61° 13′ 48.6″ | Carina | 19 700 | WC4 | Ic | |
WR 30a | 10h 51m 38.89s | −60° 56′ 34.9″ | Carina | 21 900 | WO4+O5-5.5 | Ic | |
Sher 25 | 11h 15m 07.8s | −61° 15′ 17″ | Carina | 43500+5200 −4200 [4] | B1.5Iab | [65] | |
U Scorpii | 16h 22m 30.7s | –17° 52′ 42″ | Scorpius | 64000+68000 −17000 [66] | Ia | [67] |
Red supergiants (RSGs) are stars with a supergiant luminosity class of spectral type K or M. They are the largest stars in the universe in terms of volume, although they are not the most massive or luminous. Betelgeuse and Antares A are the brightest and best known red supergiants (RSGs), indeed the only first magnitude red supergiant stars.
Solar radius is a unit of distance used to express the size of stars in astronomy relative to the Sun. The solar radius is usually defined as the radius to the layer in the Sun's photosphere where the optical depth equals 2/3:
Luminous blue variables (LBVs) are massive evolved stars that show unpredictable and sometimes dramatic variations in their spectra and brightness. They are also known as S Doradus variables after S Doradus, one of the brightest stars of the Large Magellanic Cloud. They are considered to be rare.
HR 7703 is a binary star system in the constellation of Sagittarius. The brighter component has an apparent visual magnitude of 5.31, which means it is visible from suburban skies at night. The two stars are separated by an angle of 7.10″, which corresponds to an estimated semimajor axis of 56.30 AU for their orbit.
A yellow hypergiant (YHG) is a massive star with an extended atmosphere, a spectral class from A to K, and, starting with an initial mass of about 20–60 solar masses, has lost as much as half that mass. They are amongst the most visually luminous stars, with absolute magnitude (MV) around −9, but also one of the rarest, with just 20 known in the Milky Way and six of those in just a single cluster. They are sometimes referred to as cool hypergiants in comparison with O- and B-type stars, and sometimes as warm hypergiants in comparison with red supergiants.
Westerlund 1 is a compact young super star cluster about 3.8 kpc away from Earth. It is thought to be the most massive young star cluster in the Milky Way, and was discovered by Bengt Westerlund in 1961 but remained largely unstudied for many years due to high interstellar absorption in its direction. In the future, it will probably evolve into a globular cluster.
AG Carinae is a star in the constellation Carina. It is classified as a luminous blue variable (LBV) and is one of the most luminous stars in the Milky Way. The great distance and intervening dust mean that the star is not usually visible to the naked eye; its apparent brightness varies erratically between magnitude 5.7 and 9.0.
WR 136 is a Wolf–Rayet star located in the constellation Cygnus. It is in the center of the Crescent Nebula. Its age is estimated to be around 4.7 million years and it is nearing the end of its life. Within a few hundred thousand years, it is expected to explode as a supernova.
HR Carinae is a luminous blue variable star located in the constellation Carina. It is surrounded by a vast nebula of ejected nuclear-processed material because this star has a multiple shell expanding atmosphere. This star is among the most luminous stars in the Milky Way. It has very broad emission wings on the Balmer lines, reminiscent from the broad lines observed in the spectra of O and Wolf–Rayet stars. A distance of 5 kpc and a bolometric magnitude of −9.4 put HR Car among the most luminous stars of the galaxy.
S Persei is a red supergiant or hypergiant located near the Double Cluster in Perseus, north of the cluster NGC 869. It is a member of the Perseus OB1 association and one of the largest known stars. If placed in the Solar System, its photosphere would engulf the orbit of Jupiter. It is also a semiregular variable, a star whose variations are less regular than those of Mira variables.
6 Cassiopeiae is a white hypergiant in the constellation Cassiopeia, and a small-amplitude variable star.
A hypergiant (luminosity class 0 or Ia+) is a very rare type of star that has an extremely high luminosity, mass, size and mass loss because of its extreme stellar winds. The term hypergiant is defined as luminosity class 0 (zero) in the MKK system. However, this is rarely seen in literature or in published spectral classifications, except for specific well-defined groups such as the yellow hypergiants, RSG (red supergiants), or blue B(e) supergiants with emission spectra. More commonly, hypergiants are classed as Ia-0 or Ia+, but red supergiants are rarely assigned these spectral classifications. Astronomers are interested in these stars because they relate to understanding stellar evolution, especially star formation, stability, and their expected demise as supernovae.
Cygnus OB2 is an OB association that is home to some of the most massive and most luminous stars known, including suspected Luminous blue variable Cyg OB2 #12. It also includes one of the largest known stars, NML Cygni. The region is embedded within a wider one of star formation known as Cygnus X, which is one of the most luminous objects in the sky at radio wavelengths. The region is approximately 1,570 parsecs from Earth in the constellation of Cygnus.
HD 168625 is a blue hypergiant star and candidate luminous blue variable located in the constellation of Sagittarius easy to see with amateur telescopes. It forms a visual pair with the also blue hypergiant HD 168607 and is located to the south-east of M17, the Omega Nebula.
PZ Cassiopeiae is a red supergiant star located in the constellation of Cassiopeia, and a semi-regular variable star.
NGC 4302 is an edge-on spiral galaxy located about 55 million light-years away in the constellation Coma Berenices. It was discovered by astronomer William Herschel on April 8, 1784 and is a member of the Virgo Cluster.