The following is a list of stars with resolved images, that is, stars whose images have been resolved beyond a point source.[clarification needed] Aside from the Sun, observed from Earth, stars are exceedingly small in apparent size, requiring the use of special high-resolution equipment and techniques to image. For example, Betelgeuse, the first star other than the Sun to be directly imaged, has an angular diameter of only 50 milliarcseconds (mas).[1]
![]() | This list is incomplete; you can help by adding missing items. (December 2017) |
Star | Image | Diameter | Distance (ly) |
Imager | Notes | |
---|---|---|---|---|---|---|
Angular (mas) | Geometric (Sun = 1) | |||||
Sun | ![]() |
2×106 | 1 | 0.0000158 | Various | |
Altair | ![]() |
3.2 | 1.66±0.01 (polar) 2.02±0.01 (equator) |
16.77±0.08 | CHARA array - MIRC[2] | |
Rasalhague (Alpha Ophiuchi A) | 1.62±0.03 | 2.39±0.01 (polar) 2.87±0.02 (equator) |
48.6±0.8 | CHARA array - MIRC[3] | ||
Alderamin (Alpha Cephei) | 1.35±0.02 (polar) 1.75±0.03 (equator) |
2.20±0.04 (polar) 2.74±0.04 (equator) |
48.8±0.36 | CHARA array - MIRC[3] | ||
Caph (Beta Cassiopeiae) | 1.70±0.04 | 3.1±0.1 (polar) 3.8±0.1 (equator) |
54.7±0.3 | CHARA array - MIRC[4] | ||
Regulus (Alpha Leonis A) | 1.24±0.02 | 3.2±0.1 (polar) 4.2±0.1 (equator) |
79.3±0.7 | CHARA array - MIRC[4] | ||
Algol Aa1 (Beta Persei Aa1) (stationary object) |
![]() ![]() |
0.88±0.05 | 4.13 | 93±2 | CHARA array - MIRC[5] | |
Algol Aa2 (Beta Persei Aa2) (orbiting object) |
1.12±0.07 | 3 | ||||
Algol Ab (Beta Persei Ab) | 0.56±0.10 | 0.9 | Observed radius of Algol Ab is an instrumental artifact, caused by bandwidth smearing. Actual radius is 1.73 ± 0.33 R☉. | |||
Zeta Andromedae Aa | 2.502±0.008 | 15.0±0.8 (polar) | 189±3 | CHARA array - MIRC[6][7] | First direct imaging of starspots on a star outside the Solar System. | |
R Doradus | ![]() |
57±5 | 370±50 | 204±9 | New Technology Telescope[8] | 2nd largest known star by apparent diameter in Earth's sky, after the Sun. |
Mira (Omicron Ceti) | ![]() |
50 | up to 700 | 420 | Hubble - FOC[9] | |
T Leporis | ![]() |
5.8 15 for molecular layer |
100 | 500 | Very Large Telescope - VLTI[10]/AMBER[11] | |
Pi1 Gruis | ![]() |
18.37[citation needed] | 694 | 530 | Very Large Telescope - VLTI/PIONIER[12] | First directly observed granulation patterns on a star's surface outside the Solar System. |
Antares | ![]() |
41.3±0.1 | 700 | 620 | Very Large Telescope - VLTI/AMBER[13] | |
Betelgeuse | ![]() |
50 | 630 | 643±146 | ||
Sheliak A (Beta Lyrae A) | 0.46 | 6 | 960±50 | CHARA array - MIRC[17] | ||
Theta1 Orionis C | ![]() |
0.2 | 10.6±1.5 | 1400 | Very Large Telescope - AMBER[18], GRAVITY[19] |
|
Almaaz A (Epsilon Aurigae A) | 2.27 | 3.7±0.7 | ca. 2000 | CHARA array - MIRC[20] | Supergiant with an eclipsing companion surrounded by a massive, opaque debris disk | |
HR 5171 | ![]() |
4.1±0.8 | 1575±400 | 11740±1630 | Very Large Telescope - VLTI/PIONIER[21] | Eclipsing and potential contact binary yellow hypergiant |
β Tau (Beta Tauri) | 1.09±0.076 | 4.82±0.34 | 134±2 | CHARA array [22] | ||
η UMa (Eta Ursae Majoris) | 0.834±0.060 | 2.86±0.21 | 103.9±0.8 | CHARA array [22] | ||
α Peg (Alpha Pegasi) | 1.052±0.066 | 4.62±0.29 | 133±1 | CHARA array [22] | ||