Photoevaporation is the process where energetic radiation ionises gas and causes it to disperse away from the ionising source. The term is typically used in an astrophysical context where ultraviolet radiation from hot stars acts on clouds of material such as molecular clouds, protoplanetary disks, or planetary atmospheres.
Einstein@Home is a volunteer computing project that searches for signals from spinning neutron stars in data from gravitational-wave detectors, from large radio telescopes, and from a gamma-ray telescope. Neutron stars are detected by their pulsed radio and gamma-ray emission as radio and/or gamma-ray pulsars. They also might be observable as continuous gravitational wave sources if they are rapidly spinning and non-axisymmetrically deformed. The project was officially launched on 19 February 2005 as part of the American Physical Society's contribution to the World Year of Physics 2005 event.
3C 58 or 3C58 is a pulsar and supernova remnant within the Milky Way. The object is listed as No. 58 in the Third Cambridge Catalogue of Radio Sources.
A pulsar is a highly magnetized rotating neutron star that emits beams of electromagnetic radiation out of its magnetic poles. This radiation can be observed only when a beam of emission is pointing toward Earth, and is responsible for the pulsed appearance of emission. Neutron stars are very dense and have short, regular rotational periods. This produces a very precise interval between pulses that ranges from milliseconds to seconds for an individual pulsar. Pulsars are one of the candidates for the source of ultra-high-energy cosmic rays.
The Crab Pulsar is a relatively young neutron star. The star is the central star in the Crab Nebula, a remnant of the supernova SN 1054, which was widely observed on Earth in the year 1054. Discovered in 1968, the pulsar was the first to be connected with a supernova remnant.
A millisecond pulsar (MSP) is a pulsar with a rotational period less than about 10 milliseconds. Millisecond pulsars have been detected in radio, X-ray, and gamma ray portions of the electromagnetic spectrum. The leading hypothesis for the origin of millisecond pulsars is that they are old, rapidly rotating neutron stars that have been spun up or "recycled" through accretion of matter from a companion star in a close binary system. For this reason, millisecond pulsars are sometimes called recycled pulsars.
First observed between August 4 and August 6, 1181, Chinese and Japanese astronomers recorded the supernova now known as SN 1181 in eight separate texts. One of only five supernovae in the Milky Way confidently identified in pre-telescopic records, it appeared in the constellation Cassiopeia and was visible and motionless against the fixed stars for 185 days. F. R. Stephenson first recognized that the 1181 AD "guest star" must be a supernova, because such a bright transient that lasts for 185 days and does not move in the sky can only be a galactic supernova.
PSR B0950+08 is a young pulsar that may have come from a supernova that occurred in Leo 1.8 million years ago. The large and old remnant of this supernova, located in the constellation of Antlia, may be the nearest besides the Local Bubble, and the supernova would have been as bright as the moon. Off-pulse emissions from the young pulsar were detected by the Expanded Long Wavelength Array, suggesting the presence of a pulsar wind nebula around it.
The Tolman–Oppenheimer–Volkoff limit is an upper bound to the mass of cold, non-rotating neutron stars, analogous to the Chandrasekhar limit for white dwarf stars. Stars more massive than the TOV limit collapse into a black hole. The original calculation in 1939, which neglected complications such as nuclear forces between neutrons, placed this limit at approximately 0.7 solar masses (M☉). Later, more refined analyses have resulted in larger values.
NGC 2060 is a star cluster within the Tarantula Nebula in the Large Magellanic Cloud, very close to the larger NGC 2070 cluster containing R136. It was discovered by John Herschel in 1836. It is a loose cluster approximately 10 million years old, within one of the Tarantula Nebula's superbubbles formed by the combined stellar winds of the cluster or by old supernovae.
PSR B1509−58 is a pulsar approximately 17,000 light-years away in the constellation of Circinus discovered by the Einstein X-Ray Observatory in 1982. It appears approximately 1,700 years old, and it sits in a nebula that spans about 150 light years. NASA described the star as "a rapidly spinning neutron star which is spewing energy out into the space around it to create complex and intriguing structures, including one that resembles a large cosmic hand." It is also known by the name "Hand of God". The spin rate is "almost 7 times per second".
PSR J0738−4042 is the first pulsar observed to have been affected by asteroids.
IGR J11014−6103, also called the Lighthouse Nebula, is a pulsar wind nebula trailing the neutron star which has the longest relativistic jet observed in the Milky Way galaxy.
SN 386 is a probable transient astronomical event in the constellation Sagittarius, which appeared as a "guest star" that was reported by Chinese astronomers in 386 CE.
PSR J0540−6919 is a pulsar in the Tarantula Nebula of the Large Magellanic Cloud. It is the first extragalactic gamma-ray pulsar discovered.
PSR J1856+0245 is a pulsar 9 kpc (29 kly) away from Earth. It shows similar properties to the Vela Pulsar.
PSR J0002+6216, also dubbed the Cannonball Pulsar, is a pulsar discovered by the Einstein@Home project in 2017. It is one of the fastest moving pulsars known, and has moved 53 ly (5.0×1014 km; 3.1×1014 mi) away from the location of its formation supernova, where the remaining supernova nebula, CTB 1 (Abell 85), is. Due to its speed in traversing the interstellar medium, at 1,127 km/s (700 mi/s), it is leaving a 13 ly (1.2×1014 km; 7.6×1013 mi) long wake tail and is traveling fast enough to leave the Milky Way galaxy. The pulsar is currently 6,500 ly (6.1×1016 km; 3.8×1016 mi) away in the Cassiopeia constellation. The star rotates at a rate of 8.7 times a second. There is bow-shock pulsar wind nebula (PWN) associated with PSR J0002+6216.
PSR J0740+6620 is a neutron star in a binary system with a white dwarf, located 4,600 light years away in the Milky Way galaxy. It was discovered in 2019, by astronomers using the Green Bank Telescope in West Virginia, U.S., and confirmed as a rapidly rotating millisecond pulsar.
PSR J0952–0607 is a massive millisecond pulsar in a binary system, located between 3,200–5,700 light-years (970–1,740 pc) from Earth in the constellation Sextans. It holds the record for being the most massive neutron star known as of 2022, with a mass 2.35±0.17 times that of the Sun—potentially close to the Tolman–Oppenheimer–Volkoff mass upper limit for neutron stars. The pulsar rotates at a frequency of 707 Hz, making it the second-fastest-spinning pulsar known, and the fastest-spinning pulsar known within the Milky Way.
Kesteven 75, abbreviated as Kes 75 and also called SNR G029.7-00.3, G29.7-0.3 and 4C -03.70, is a supernova remnant located in the constellation Aquila.
