The hottest stars

The hottest star in gravityfinder is NN Ser, with a measured surface temperature of about 57,000 K, roughly 10 times the Sun's 5,772 K.

Surface temperature decides a star's colour: our own Sun runs at about 5,772 K and looks yellow-white, while the stars at the top of this list burn blue at ten times that.

#	Star	Temperature	Class	Distance	Magnitude
1	NN Ser	57,000 K	WD	1,682 ly	16.94
2	VFTS 682	54,450 K	Wolf-Rayet star (WN5h)	163,000 ly	16.08
3	Melnick 34	53,000 K	Wolf-Rayet binary (WN5h + WN5h)	163,000 ly	13.09
4	HD 269810	52,500 K	O-type giant (O2 III)	163,000 ly	12.22
5	Melnick 42	47,300 K	O-type supergiant (O2 If)	163,000 ly	12.78
6	R136a2	47,000 K	Wolf-Rayet star (WN5h)	163,000 ly	12.34
7	R136a1	46,000 K	Wolf-Rayet star (WN5h)	163,000 ly	12.23
8	HD 5980	45,000 K	Wolf-Rayet + blue-variable system	200,000 ly	–
9	NSVS 14256825	40,000 K	O-type	2,677 ly	13.30
10	Romano's Star	33,000 K	Luminous blue variable (post-LBV)	2.7 million ly	18.00
11	NY Vir	32,780 K	O-type	1,774 ly	13.50
12	Mintaka	30,100 K	Hot blue giant multiple star	1,246 ly	2.41
13	2MASS J19383260+4603591	29,564 K	B-type	1,293 ly	12.65
14	Alnitak	29,500 K	Hot blue supergiant	1,260 ly	1.77
15	V0391 Peg	29,300 K	sdBV	3,901 ly	14.77
16	Acrux	28,950 K	Blue subgiant (multiple system)	348 ly	0.76
17	Mimosa	28,840 K	Blue giant	280 ly	1.25
18	KOI-55	27,730 K	B	4,015 ly	15.15
19	KIC 10001893	27,500 K	B-type	5,456 ly	15.83
20	Saiph	25,700 K	Blue supergiant	650 ly	2.06
21	Spica	25,300 K	Blue giant (close binary)	250 ly	0.97
22	Hadar	25,000 K	Blue giant	361 ly	0.61
23	Alnilam	25,000 K	Blue supergiant	1,250 ly	1.69
24	Sirius B	25,000 K	White dwarf (DA2)	8.6 ly	8.44
25	Bellatrix	21,840 K	Hot blue giant star	252 ly	1.64
26	mu2 Sco	21,700 K	B2 IV	–	3.56
27	Sanduleak -69° 202	16,000 K	Blue supergiant (B3 Ia)	163,000 ly	12.00
28	ZTF J1828+2308	15,900 K	B-type	658 ly	18.04
29	Achernar	15,000 K	Blue-white main-sequence star	140 ly	0.46
30	HIP 77900	13,646 K	B-type	492 ly	6.15
31	DP Leo	13,500 K	B-type	997 ly	18.68
32	Algol	13,000 K	Blue-white eclipsing binary	93.0 ly	2.12
33	Rigel	12,130 K	Blue supergiant	860 ly	0.13
34	Regulus	11,535 K	Blue-white main-sequence star	79.3 ly	1.40
35	kap And	11,327 K	B9 IVn	163 ly	4.14
36	HIP 78530	10,500 K	B9 V	446 ly	7.17
37	HD 100546	10,500 K	B9 Vne	358 ly	6.69
38	WD 0806-661	10,393 K	DQ	62.8 ly	13.86
39	HD 97048	10,000 K	Be9.5/AO	600 ly	8.44
40	ZTF J1230-2655	10,000 K	B-type	609 ly	18.91
41	Castor	9,900 K	Blue-white six-star system	49.2 ly	1.58
42	Sirius	9,797 K	Blue-white main-sequence star	8.6 ly	-1.46
43	AB Aur	9,770 K	A-type	529 ly	7.08
44	Vega	9,550 K	Blue-white main-sequence star	25.0 ly	0.03
45	HD 135344 A	9,540 K	A0 V	462 ly	7.76
46	WASP-178	9,360 K	A1 IV-V	1,395 ly	9.95
47	KELT-9	9,270 K	A	667 ly	7.55
48	HIP 79098 AB	9,194 K	B9 V	476 ly	5.86
49	S Doradus	9,000 K	Luminous blue variable	163,000 ly	10.05
50	Mizar	9,000 K	Blue-white multiple star	82.9 ly	2.04

Showing 50 of 4,535 stars that qualify.

Common questions

What is the hottest star?

The hottest star in gravityfinder is NN Ser, with a measured surface temperature of about 57,000 K, roughly 10 times the Sun's 5,772 K.

How was this list put together?

The top of this list is not always a normal star: a white dwarf is the exposed core of a dead one, and it starts out hotter than any living stellar surface. This ranking uses measured values only: stellar parameters from the NASA Exoplanet Archive for host stars, and the published literature for the curated famous stars. The naked-eye catalog's temperatures are estimated from colour index and its luminosities from absolute magnitude, which are good enough to describe a star and not good enough to rank one, so those stars sit this list out.

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