SS 433 is a

microquasar A microquasar, a smaller version of a quasar, is a compact region surrounding a stellar black hole with a mass several times that of its companion star, observable in sufficient details, in our own or nearby galaxy. The matter being pulled from ...

or eclipsing X-ray binary

system A system is a group of interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its open system (systems theory), environment, is described by its boundaries, str ...

, consisting of a stellar-mass

black hole A black hole is a massive, compact astronomical object so dense that its gravity prevents anything from escaping, even light. Albert Einstein's theory of general relativity predicts that a sufficiently compact mass will form a black hole. Th ...

accreting matter from an A-type

companion star A binary star or binary star system is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved as separate stars us ...

. SS 433 is the first discovered microquasar. 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 Case Western Reserve University (CWRU) is a Private university, private research university in Cleveland, Ohio, United States. It was established in 1967 by a merger between Western Reserve University and the Case Institute of Technology. Case ...

: Nicholas Sanduleak and Charles Bruce Stephenson. It was the 433rd entry in their 1977 catalog of stars with strong emission lines.SS 433
David Darling, entry in ''The Internet Encyclopedia of Science'', accessed on line September 14, 2007. Its emission lines were studied by Mordehai Milgrom in 1979.

Location

SS 433, also known as V1343 Aquilae, located in the galactic plane (''l= 39.7° and b= -2.2°''), at a distance of .

System

The compact central object is consuming the companion star which rapidly loses mass into an

accretion disc An accretion disk is a structure (often a circumstellar disk) formed by diffuse material in orbital motion around a massive central body. The central body is most frequently a star. Friction, uneven irradiance, magnetohydrodynamic effects, and ...

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 The speed of light in vacuum, commonly denoted , is a universal physical constant exactly equal to ). It is exact because, by international agreement, a metre is defined as the length of the path travelled by light in vacuum during a time i ...

. 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

solar mass The solar mass () is a frequently used unit of mass in astronomy, equal to approximately . It is approximately equal to the mass of the Sun. It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxie ...

es. 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 seconds per second, or about 3 seconds per year.

Observational data

The jets from the primary are emitted perpendicular to its

accretion disk An accretion disk is a structure (often a circumstellar disk) formed by diffuse material in orbital motion around a massive central body. The central body is most frequently a star. Friction, uneven irradiance, magnetohydrodynamic effects, and ...

. The jets and disk

precess Precession is a change in the orientation of the rotational axis of a rotating body. In an appropriate reference frame it can be defined as a change in the first Euler angle, whereas the third Euler angle defines the rotation itself. In ot ...

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. Precession means that the jets sometimes point more towards the Earth, and sometimes more away, producing both blue and red

Doppler shift The Doppler effect (also Doppler shift) is the change in the frequency of a wave in relation to an observer who is moving relative to the source of the wave. The ''Doppler effect'' is named after the physicist Christian Doppler, who described t ...

s in the observed visible spectrum. Also, the precession means that the jets corkscrew through space in an expanding helical spray. As they impact the surrounding W50 supernova remnant clouds, they distort it into an elongated shape. PIA24574-SS433-ULXray-20210709

Observations in 2004 by the

Very Long Baseline Array The Very Long Baseline Array (VLBA) is a system of ten radio telescopes which are operated remotely from their Array Operations Center located in Socorro, New Mexico, as a part of the National Radio Astronomy Observatory (NRAO). These ten radio ...

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. The spectrum of SS 433 is affected not just by

s 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 The kilometre ( SI symbol: km; or ), spelt kilometer in American and Philippine English, is a unit of length in the International System of Units (SI), equal to one thousand metres (kilo- being the SI prefix for ). It is the preferred measu ...

per

second The second (symbol: s) is a unit of time derived from the division of the day first into 24 hours, then to 60 minutes, and finally to 60 seconds each (24 × 60 × 60 = 86400). The current and formal definition in the International System of U ...

. This does not represent an actual velocity of the system away from the Earth; rather, it is due to

time dilation Time dilation is the difference in elapsed time as measured by two clocks, either because of a relative velocity between them (special relativity), or a difference in gravitational potential between their locations (general relativity). When unsp ...

, 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. In September 2018, A. U. Abeysekara et al. published in ''

Nature Nature is an inherent character or constitution, particularly of the Ecosphere (planetary), ecosphere or the universe as a whole. In this general sense nature refers to the Scientific law, laws, elements and phenomenon, phenomena of the physic ...

'' details of investigations using the High-Altitude Water Cherenkov Gamma-Ray (HAWC) Observatory in

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

. They reported teraelectronvolt γ-ray observations exceeding 25 TeV 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 micro

gauss Johann Carl Friedrich Gauss (; ; ; 30 April 177723 February 1855) was a German mathematician, astronomer, Geodesy, geodesist, and physicist, who contributed to many fields in mathematics and science. He was director of the Göttingen Observat ...

.Scientists discover new nursery for superpowered photons
Space Daily, 2018-10-04

In popular culture

In '' SNL'' season 4 (1979), Father Guido Sarducci mentions SS 433. In the ''Seven Wonders of The World'' documentary series, Arthur C. Clarke mentions SS 433 as one of his "seven wonders of the universe". In his novel ''

House of Suns ''House of Suns'' is a 2008 in literature, 2008 science fiction novel by Wales, Welsh author Alastair Reynolds. The novel was shortlisted for the 2009 Arthur C. Clarke Award. Setting Approximately six million years in the future, humanity has s ...

,''

Alastair Reynolds Alastair Preston Reynolds (born 13 March 1966) is a Welsh science fiction author. He specialises in hard science fiction and space opera. Early life Reynolds was born in Wales and spent his early years in Cornwall before moving back to Wales, ...

describes a fictional star in the

Andromeda galaxy The Andromeda Galaxy is a barred spiral galaxy and is the nearest major galaxy to the Milky Way. It was originally named the Andromeda Nebula and is cataloged as Messier 31, M31, and NGC 224. Andromeda has a Galaxy#Isophotal diameter, D25 isop ...

as "a close cousin" to SS 433.

Location

System

Observational data

In popular culture

See also

References

Further reading