SS 433 at the centre of supernova remnant W50 Credit: NRAO/AUI/NSF, K. Golap, M. Goss; NASA’s Wide Field Survey Explorer (WISE) | |
Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Aquila |
Right ascension | 19h 11m 49.56s [1] |
Declination | +04° 58′ 57.8″ [1] |
Apparent magnitude (V) | 13.0 - 17.3 [2] |
Characteristics | |
Spectral type | A7Ib |
Variable type | Eclipsing binary [2] |
Astrometry | |
Proper motion (μ) | RA: −3.027 [1] mas/yr Dec.: −4.777 [1] mas/yr |
Parallax (π) | 0.1182 ± 0.0233 mas [1] |
Distance | 18,000±700 ly (5,500±200 [3] [4] pc) |
Orbit [5] | |
Period (P) | 13.082 d |
Eccentricity (e) | 0.05 ± 0.01 |
Inclination (i) | 79° |
Other designations | |
V1343 Aql, GAL 039.7-02.0, 2MASS J19114957+0458578, USNO 659, 1A 1909+04, 87GB 190920.8+045332, NEK 40.1-02.1, 3A 1909+048, GPS 1909+049, RGB J1911+049, BWE 1909+0453, GRS 039.60 -01.80, RX J1911.7+0459, 4C 04.66, 1H 1908+047, 1RXS J191149.7+045857, 2E 1909.3+0453, HBHA 204-02, AAVSO 1906+04, 2E 4204, INTEGRAL1 110, TXS 1909+048, 1ES 1909+04.8, INTREF 969, 4U 1908+05. | |
Database references | |
SIMBAD | data |
SS 433 is a microquasar or eclipsing X-ray binary system, consisting of a stellar-mass black hole accreting matter from an A-type companion star. [5] [6] SS 433 is the first discovered microquasar. [7] It is at the centre of the supernova remnant W50.
SS 433's designation comes from the initials of two astronomers at Case Western Reserve University: Nicholas Sanduleak and Charles Bruce Stephenson. It was the 433rd entry in their 1977 catalog of stars with strong emission lines. [7] Its emission lines were studied by Mordehai Milgrom in 1979. [8]
SS 433, also known as V1343 Aquilae, located in the galactic plane (l= 39.7° and b= -2.2°), at a distance of 5.5 kpc.
The compact central object is consuming the companion star which rapidly loses mass into an accretion disc formed around the central object. The accretion disc is subject to extreme heating as it spirals into the primary and this heating causes the accretion disc to give off intense X-rays and opposing jets of hot hydrogen along the axis of rotation, above and below the plane of the accretion disc. The material in the jets travels at 26% of the speed of light. [9] The companion star presumably had lower mass than the original primary object and was therefore longer lived. Estimates for its mass range from 3 to 30 [10] solar masses. The primary and secondary orbit each other at a very close distance in stellar terms, with an orbital period of 13.082 days. Their orbit is very slightly eccentric, and its period is slowly increasing at a rate of about 1.0×10−7 seconds per second, or about 3 seconds per year. [5]
The jets from the primary are emitted perpendicular to its accretion disk. The jets and disk precess around an axis inclined about 79° to a line between Earth and SS 433. The angle between the jets and the axis is around 20°, and the precessional period is around 162.5 days. [12] Precession means that the jets sometimes point more towards the Earth, and sometimes more away, producing both blue and red Doppler shifts in the observed visible spectrum. [9] Also, the precession means that the jets corkscrew through space in an expanding helical spray. [13] As they impact the surrounding W50 supernova remnant clouds, they distort it into an elongated shape. [14]
Observations in 2004 by the Very Long Baseline Array for 42 consecutive days gave new data and understanding of the action of the jets. It appears that the jets are sometimes impacting material shortly after being created and thus brightening. The material the jets are impacting appears to be replaced some of the time, but not always, leading to variations in the brightening of the jets. [15] [16]
The spectrum of SS 433 is affected not just by Doppler shifts but also by relativity: when the effects of the Doppler shift are subtracted, there is a residual redshift which corresponds to a velocity of about 12,000 kilometers per second. This does not represent an actual velocity of the system away from the Earth; rather, it is due to time dilation, which makes moving clocks appear to stationary observers to be ticking more slowly. In this case, the relativistically moving excited atoms in the jets appear to vibrate more slowly and their radiation thus appears red-shifted. [9]
In September 2018, A. U. Abeysekara et al. published in Nature details of investigations using the High-Altitude Water Cherenkov Gamma-Ray (HAWC) Observatory in Mexico. They reported teraelectronvolt γ-ray observations exceeding 25TeV of the SS 433/W50 system that spatially resolve the lobes, and consistent with a single population of electrons with energies extending to at least hundreds of teraelectronvolts in a magnetic field of about 16 microgauss. [17] [18]
In SNL Season 4 (1979), Father Guido Sarducci mentions SS 433. [19]
In the Seven Wonders of The World documentary series, Arthur C. Clarke mentions SS 443 as one of his "seven wonders of the universe". [20]
In his novel House of Suns, Alastair Reynolds describes a fictional star in the Andromeda galaxy as "a close cousin" to SS433. [21]
Cygnus X-1 (abbreviated Cyg X-1) is a galactic X-ray source in the constellation Cygnus and was the first such source widely accepted to be a black hole. It was discovered in 1971 during a rocket flight and is one of the strongest X-ray sources detectable from Earth, producing a peak X-ray flux density of 2.3×10−23 W/(m2⋅Hz) (2.3×103 jansky). It remains among the most studied astronomical objects in its class. The compact object is now estimated to have a mass about 21.2 times the mass of the Sun and has been shown to be too small to be any known kind of normal star or other likely object besides a black hole. If so, the radius of its event horizon has 300 km "as upper bound to the linear dimension of the source region" of occasional X-ray bursts lasting only for about 1 ms.
X-ray binaries are a class of binary stars that are luminous in X-rays. The X-rays are produced by matter falling from one component, called the donor, to the other component, called the accretor, which is either a neutron star or black hole. The infalling matter releases gravitational potential energy, up to 30 percent of its rest mass, as X-rays. The lifetime and the mass-transfer rate in an X-ray binary depends on the evolutionary status of the donor star, the mass ratio between the stellar components, and their orbital separation.
An astrophysical jet is an astronomical phenomenon where outflows of ionised matter are emitted as extended beams along the axis of rotation. When this greatly accelerated matter in the beam approaches the speed of light, astrophysical jets become relativistic jets as they show effects from special relativity.
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A Type Ia supernova is a type of supernova that occurs in binary systems in which one of the stars is a white dwarf. The other star can be anything from a giant star to an even smaller white dwarf.
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GRS 1915+105 or V1487 Aquilae is an X-ray binary star system which features a regular star and a black hole. It was discovered on August 15, 1992 by the WATCH all-sky monitor aboard Granat. "GRS" stands for "GRANAT source", "1915" is the right ascension and "105" reflects the approximate declination. The near-infrared counterpart was confirmed by spectroscopic observations. The binary system lies 11,000 parsecs away in Aquila. GRS 1915+105 is the heaviest of the stellar black holes so far known in the Milky Way Galaxy, with 10 to 18 times the mass of the Sun. It is also a microquasar, and it appears that the black hole rotates at least 950 times per second, close to the maximum of 1,150 times per second, with a spin parameter value between 0.82 and 1.00.
WR 136 is a Wolf–Rayet star located in the constellation Cygnus. It is in the center of the Crescent Nebula. Its age is estimated to be around 4.7 million years and it is nearing the end of its life. Within a few hundred thousand years, it is expected to explode as a supernova.
4U 1700-37 is one of the stronger binary X-ray sources in the sky, and is classified as a high-mass X-ray binary. It was discovered by the Uhuru satellite. The "4U" designation refers to the fourth Uhuru catalog.
56 Pegasi is a binary star system in the northern constellation of Pegasus. It is visible to the naked eye with a combined apparent visual magnitude of 4.74. The system is approximately 590 light years away from the Sun based on parallax, but is drifting closer with a radial velocity of −28 km/s. It is listed as a member of the Wolf 630 moving group.
W Serpentis is an eclipsing binary star in the constellation Serpens. It is always too faint to be seen with the naked eye, varying between apparent magnitudes 8.42 and 10.2 with a period of just over 14 days. This is mainly due to eclipses; however, variations in its period indicate there are some innate changes in luminosity of one or both component stars as they interact with each other, and it has been difficult to disentangle the light to determine their nature. The period is increasing by 14 seconds a year, indicating that a massive amount of material is being transferred from the larger fainter star to the smaller brighter one.
UW Coronae Borealis, also known as MS 1603.6+2600, is a low-mass X-ray binary star system in the constellation Corona Borealis. Astronomer Simon Morris and colleagues discovered the X-ray source in 1990 and were able to match it up with a faint star with an average visual magnitude of 19.4. The system is thought to be made up of a neutron star that has an accretion disk that draws material from its companion, a star less massive than the Sun. The disk is asymmetrical. The variability of the system is complex, with several periods identified: the two components orbit each other every 111 minutes, while there is another period of 112.6 minutes. The beat period of these is 5.5 days, which is thought to represent the precession of the asymmetrical accretion disk around the neutron star.
A circumstellar disc is a torus, pancake or ring-shaped accretion disk of matter composed of gas, dust, planetesimals, asteroids, or collision fragments in orbit around a star. Around the youngest stars, they are the reservoirs of material out of which planets may form. Around mature stars, they indicate that planetesimal formation has taken place, and around white dwarfs, they indicate that planetary material survived the whole of stellar evolution. Such a disc can manifest itself in various ways.
XTE J1118+480 is a low-mass X-ray binary in the constellation Ursa Major. It is a soft X-ray transient that most likely contains a black hole and is probably a microquasar.
CH Cygni is a red giant, variable, symbiotic binary in the constellation Cygnus. It is the nearest symbiotic star to Earth, and one of the brightest, making it an ideal candidate for study.
Gustavo E. Romero is a professor of Relativistic Astrophysics at the University of La Plata in Argentina. In addition to his academic role, he serves as a Superior Researcher of the National Research Council of Argentina. Romero also holds the position of Director of the Argentine Institute of Radio Astronomy (IAR). Additionally, Romero has previously served as President of the Argentine Astronomical Society and is currently the leader of the GARRA research group and a Helmholtz International Fellow.
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TX Ursae Majoris is an eclipsing binary star system in the northern circumpolar constellation of Ursa Major. With a combined apparent visual magnitude of 6.97, the system is too faint to be readily viewed with the naked eye. The pair orbit each other with a period of 3.063 days in a circular orbit, with their orbital plane aligned close to the line of sight from the Earth. During the primary eclipse, the net brightness decreases by 1.74 magnitudes, while the secondary eclipse results in a drop of just 0.07 magnitude. TX UMa is located at a distance of approximately 780 light years from the Sun based on parallax measurements, but is drifting closer with a mean radial velocity of −13 km/s.
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DW Ursae Majoris is an eclipsing binary star system in the northern circumpolar constellation of Ursa Major, abbreviated DW UMa. It is a cataclysmic variable of the SX Sextanis type, consisting of a compact white dwarf that is accreting matter from an orbiting companion star. The brightness of this source ranges from an apparent visual magnitude of 13.6 down to magnitude 18, which is too faint to be viewed with the naked eye. The distance to this system is approximately 1,920 light years based on parallax measurements.