List of most massive neutron stars

Below is a list of high-mass neutron stars.

Name	Mass (M☉)	Distance (ly)	Companion class	Mass determination method	Notes	Refs.
PSR J1748-2021B	2.548+0.047 −0.078	27,700	D	Rate of advance of periastron.	In globular cluster NGC 6440.	[1][2][3][4]
4U 1700-37	2.44±0.27	6,910 ± 1,120	O6.5Iaf+	Monte Carlo simulations of thermal comptonization process.	HMXB system.	[5][6]
PSR J2017-1614	2.4±0.6	4,570	Substellar object		Black widow pulsar, in a tight 2.3 hour binary.	[7]
PSR J0952–0607	2.35±0.17	3,200–5,700	Substellar object	Radio-measured Shapiro delay	Black widow pulsar. Fastest spinning galactic pulsar.	[8]
PSR J1311–3430	2.15–2.7	6,500–12,700	Substellar object	Spectroscopic and photometric observation.	Black widow pulsar.	[9][10]
PSR J1600−3053	2.3+0.7 −0.6	6,500 ± 1,000	D	Fourier analysis of Shapiro delay's orthometric ratio.		[11][12]
PSR J2215+5135	2.27+0.17 −0.15	10,000	G5V	Innovative measurement of companion's radial velocity.	Redback pulsar.	[13]
XMMU J013236.7+303228	2.2+0.8 −0.6	2,730,000	B1.5IV	Detailed spectroscopic modelling.	In M33, HMXB system.	[14]
PSR J0751+1807	2.10±0.2	6,500 ± 1,300	D	Precision pulse timing measurements of relativistic orbital decay.		[15]
PSR J0740+6620	2.08±0.07	4,600	D	Range and shape parameter of Shapiro delay.	Most massive neutron star with a well-constrained mass.	[16][17][18]
PSR J0348+0432	2.01±0.04	2,100	D	Spectroscopic observation and orbital decay due to radiation of gravitational waves.		[11][19]
PSR J1518+0204B (M5B)	1.981	24,500	M6-8V?		In the globular cluster, M5. In a 7 day binary with a low-mass 0.11-0.13 M☉ red dwarf.	[20]
PSR B1516+02B	1.94+0.17 −0.19	24,500	D	Rate of advance of periastron.	In globular cluster M5.	[11][21]
PSR J1614−2230	1.908±0.016	3,900	D	Range and shape parameter of Shapiro delay.	In Milky Way's galactic disk.	[11][12][22]
Vela X-1	1.88±0.13	6,200 ± 650	B0.5Ib	Rate of advance of periastron.	Prototypical detached HMXB system.	[23]
PSR J2222–0137	1.831	871	D		Companion is a white dwarf which is one of the most massive at 1.319 M☉	[24]
PSR B1957+20	1.81±0.17	6,500	Substellar object	Rate of advance of periastron.	Prototype star of black widow pulsars.	[25][26][27]
SWIFT J1756.9-2508	1.8±0.4	26,100	Substellar object		Hosts one planet, it is notable for orbiting its star in 54 minutes.	[28][29]

See also

• Astronomy portal
• Physics portal

• Blitzar
• List of least massive black holes
• List of most massive black holes
• List of neutron stars
• Tolman–Oppenheimer–Volkoff limit
• Quark star