List of star extremes
A star is a sphere that is mainly composed of hydrogen and plasma, held together by gravity and is able to produce light through nuclear fusion. Stars exhibit many diverse properties, resulting from different masses, volumes, velocities, stage in stellar evolution and even proximity to earth. Some of these properties are considered extreme and sometimes disproportionate by astronomers.
Age and distance
Title | Object | Date | Data | Comments | Notes | Refs | See more |
Nearest "average" star | Alpha Centauri A & B | 1839 | This was the third star whose parallax was determined. Before Alpha Cen, the record was held by 61 Cygni, the first star whose parallax was determined. | ||||
Nearest normal star | Alpha Centauri C | 1915 | Before Proxima, the title had been held by Alpha Centauri A&B. | ||||
Nearest red dwarf | Alpha Centauri C | 1915 | Before Proxima, the title had been held by Barnard's Star | ||||
Nearest degenerate star | Sirius B | 1852 | This is also the nearest white dwarf | ||||
Nearest borderline subgiant | Procyon | All stars closer to the Sun are either main sequence or dwarf stars. | |||||
Nearest undisputed subgiant | Delta Pavonis | A subgiant, but only slightly brighter than the Sun. | |||||
Nearest "true" giant star | Pollux | ||||||
Nearest red giant | Arcturus | ||||||
Nearest spectral type A or hotter | Sirius | ||||||
Nearest neutron star | RX J185635-3754 | 2000 | |||||
Nearest white dwarf | Sirius B | 1852 | Sirius B is also the second white dwarf discovered, after 40 Eridani B. | ||||
Nearest flare star | Proxima Centauri | α Cen C is also the nearest neighbouring star. | |||||
Nearest brown dwarf | 2013 | This is a pair of brown dwarfs in a binary system, with no other stars. |
Brightness and power
Title | Object | Date | Data | Comments | Notes | Refs | See more |
Brightest star from the Earth: Apparent magnitude | Sun | prehistoric | Reported for reference | ||||
Brightest star other than the Sun | Sirius | prehistoric | m=−1.46 | List of brightest stars | |||
Brightest star in a transient event | Progenitor of SN 1006 | 1006 | m=−7.5 | This was a supernova, and its remnant is catalogued as PKS 1459-41 | |||
Dimmest star from the Earth | UDF 2457 | - | - | - | |||
Most luminous star | R136a1 | 2010 | List of most luminous stars | ||||
Most luminous star in a transient event | Progenitor of GRB 080916C | 2008 | The star exploded in a gamma-ray burst with the total energy equal to 9,000 supernovae | List of gamma-ray bursts | |||
Least luminous normal star | 2MASS J0523−1403 | 2013 | |||||
Most energetic star | R136a1 | 2010 | List of most luminous stars | ||||
Most energetic star in a transient event | Progenitor of GRB 080916C | 2008 | |||||
Least energetic normal star | 2MASS J0523−1403 | 2013 | L=0.000126LSun | ||||
Hottest normal star | WR 102 | T=210000 K | List of hottest stars | ||||
Coolest normal star | S Cassiopeiae | T=1800 K | List of coolest stars |
Title | Object | Date | Data | Comments | Notes | Refs | See more |
Hottest degenerate star | KPD 0005+5106 H1504+65 | 2008 | 200,000 K 200,000 K | ||||
Hottest neutron star | At least 100,000K | ||||||
Hottest white dwarf | KPD 0005+5106 | 2008 | 200,000 K | ||||
Hottest PG 1159 star/GW Vir star | RX J2117+3412 | 1999 | 170,000 K | ||||
Coolest brown dwarf | WISE 1828+2650 | 250–400 K | WISE 0855-0714 may be cooler at 225–260 K, but its status as a rogue planet or sub-brown dwarf is not well known as its mass is between. |
Size and mass
Motion
Star systems
Title | Object | Date | Data | Comments | Notes | Refs | See more |
Shortest period black hole binary system | 2013 | This exceeds the preceding recordholder by about one hour |
Location
The southern hemisphere consists of more 1st magnitude stars than the northern.Due to precession this will change over the centuries, by AD 13800, Vega will be only 4 degrees from the North Pole, at the same time Canopus will be 10 degrees from the South pole. At that time, the number of bright stars in the northern hemisphere will be only 6 while 17 in the southern. Moreover, due to proper motion some nearby stars like Arcturus or Alpha Centauri will be displaced several degrees. About AD 6400 Alpha Centauri will pass 1 degree from Beta Centauri.
At BC 3400, Achernar was only 8 degrees from the South Pole.
The greatest concentration of bright stars is around Orion. Within a circle of 60 degrees radius around a point in Monoceros at RA 6:30, DE 5ºS, 11 stars of magnitude +1.6 or brighter occur: Capella, Pollux, Castor, Regulus, Procyon, Sirius, Adhara, Canopus, Rigel, Betelgeuse and Aldebaran. No other part of the sky consists of so many bright stars: the entire sky has just 23 such stars.
Narrowing the circle to 50 degrees and moving the center to the midway point of Capella and Canopus will still consist of 9 stars leaving out only Regulus.
Within a much smaller circle of 10 degrees radius from Alnilam, the center Orion belt star, 5 stars of mag +2.2 or brighter occur of which 70 exist in the entire sky.
The most 'remote' first magnitude star from another first magnitude star is either Fomalhaut or Achernar which are nearest to each other, then Antares which is nearest to Alpha Centauri.