A report on Binary star

Edge-on disc of gas and dust present around the binary star system HD 106906

Algol B orbits Algol A. This animation was assembled from 55 images of the CHARA interferometer in the near-infrared H-band, sorted according to orbital phase.

Artist's conception of a cataclysmic variable system

Artist's impression of the binary star system AR Scorpii

Artist rendering of plasma ejections from V Hydrae

Artist's impression of the sight from a (hypothetical) moon of planet HD 188753 Ab (upper left), which orbits a triple star system. The brightest companion is just below the horizon.

Schematic of a binary star system with one planet on an S-type orbit and one on a P-type orbit

The two visibly distinguishable components of Albireo

Luhman 16, the third closest star system, contains two brown dwarfs.

System of two stars that are gravitationally bound to and in orbit around each other.

- Binary star

93 related topics with Alpha

Star

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Astronomical object comprising a luminous spheroid of plasma held together by its gravity.

Infrared image from NASA's Spitzer Space Telescope showing hundreds of thousands of stars in the Milky Way galaxy

Stellar evolution of low-mass (left cycle) and high-mass (right cycle) stars, with examples in italics

An example of a Hertzsprung–Russell diagram for a set of stars that includes the Sun (center) (see Classification)

Betelgeuse as seen by ALMA. This is the first time that ALMA has observed the surface of a star and resulted in the highest-resolution image of Betelgeuse available.

Onion-like layers at the core of a massive, evolved star just before core collapses

The Crab Nebula, remnants of a supernova that was first observed around 1050 AD

Artist's impression of the Sirius system, a white dwarf star in orbit around an A-type main-sequence star

This view of NGC 6397 includes stars known as blue stragglers for their location on the Hertzsprung–Russell diagram.

Some of the well-known stars with their apparent colors and relative sizes

The Pleiades, an open cluster of stars in the constellation of Taurus. These stars share a common motion through space.

Surface magnetic field of SU Aur (a young star of T Tauri type), reconstructed by means of Zeeman–Doppler imaging

The reflection nebula NGC 1999 is brilliantly illuminated by V380 Orionis. The black patch of sky is a vast hole of empty space and not a dark nebula as previously thought.

The asymmetrical appearance of Mira, an oscillating variable star

Internal structures of main sequence stars with masses indicated in solar masses, convection zones with arrowed cycles, and radiative zones with red flashes. Left to right, a red dwarf, a yellow dwarf, and a blue-white main sequence star

Overview of consecutive fusion processes in massive stars

Stars can form orbital systems with other astronomical objects, as in the case of planetary systems and star systems with two or more stars.

White dwarf

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Stellar core remnant composed mostly of electron-degenerate matter.

A comparison between the white dwarf IK Pegasi B (center), its A-class companion IK Pegasi A (left) and the Sun (right). This white dwarf has a surface temperature of 35,500 K.

The white dwarf cooling sequence seen by ESA's Gaia mission

Artist's impression of the WD J0914+1914 system.

Internal structures of white dwarfs. To the left is a newly formed white dwarf, in the center is a cooling and crystallizing white dwarf, and the right is a black dwarf.

Artist's impression of debris around a white dwarf

Comet falling into white dwarf (artist's impression)

The merger process of two co-orbiting white dwarfs produces gravitational waves

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The nearest known white dwarf is Sirius B, at 8.6 light years, the smaller component of the Sirius binary star.

Artist's conception of a white dwarf, right, accreting hydrogen from the Roche lobe of its larger companion star

Nova

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Transient astronomical event that causes the sudden appearance of a bright, apparently "new" star (hence the name "nova", which is Latin for "new") that slowly fades over weeks or months.

Nova Eridani 2009 (apparent magnitude ~8.4)

All observed novae involve white dwarfs in close binary systems.

Black hole

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Region of spacetime where gravity is so strong that nothing – no particles or even electromagnetic radiation such as light – can escape from it.

Animated simulation of a Schwarzschild black hole with a galaxy passing behind. Around the time of alignment, extreme gravitational lensing of the galaxy is observed.

Simulated view of a black hole in front of the Large Magellanic Cloud. Note the gravitational lensing effect, which produces two enlarged but highly distorted views of the Cloud. Across the top, the Milky Way disk appears distorted into an arc. Published in 2019.

Gravitational time dilation around a black hole

The ergosphere is a region outside of the event horizon, where objects cannot remain in place.

Gas cloud being ripped apart by black hole at the centre of the Milky Way (observations from 2006, 2010 and 2013 are shown in blue, green and red, respectively).

Artist's impression of supermassive black hole seed

Simulated event in the CMS detector: a collision in which a micro black hole may be created

This artist's impression depicts the paths of photons in the vicinity of a black hole. The gravitational bending and capture of light by the event horizon is the cause of the shadow captured by the Event Horizon Telescope.

Predicted appearance of a non-rotating black hole with toroidal ring of ionised matter, such as has been proposed as a model for Sagittarius A*. The asymmetry is due to the Doppler effect resulting from the enormous orbital speed needed for centrifugal balance of the powerful gravitational attraction of the hole.

Black hole with corona, X-ray source (artist's concept)

NASA simulated view from outside the horizon of a Schwarzschild black hole lit by a thin accretion disk.

Blurring of X-rays near black hole (NuSTAR; 12 August 2014)

A Chandra X-Ray Observatory image of Cygnus X-1, which was the first strong black hole candidate discovered

Magnetic waves, called Alfvén S-waves, flow from the base of black hole jets.

Detection of unusually bright X-Ray flare from Sagittarius A*, a black hole in the centre of the Milky Way galaxy on 5January 2015

Simulation of gas cloud after close approach to the black hole at the centre of the Milky Way.

An infographic explaining in detail the appearance of a black hole. The photon sphere surrounds the black hole's shadow.

In this way, astronomers have identified numerous stellar black hole candidates in binary systems and established that the radio source known as Sagittarius A*, at the core of the Milky Way galaxy, contains a supermassive black hole of about 4.3 million solar masses.

$Hubble Space Telescope image of Sirius A and Sirius B. The white dwarf can be seen to the lower left. The diffraction spikes and concentric rings are instrumental effects.$

Sirius

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Brightest star in the night sky.

$Hubble Space Telescope image of Sirius A and Sirius B. The white dwarf can be seen to the lower left. The diffraction spikes and concentric rings are instrumental effects.$

Sirius (bottom) and the constellation Orion (right). The three brightest stars in this image—Sirius, Betelgeuse (top right) and Procyon (top left)—form the Winter Triangle. The bright star at top center is Alhena, which forms a cross-shaped asterism with the Winter Triangle.

The orbit of Sirius B around A as seen from Earth (slanted ellipse). The wide horizontal ellipse shows the true shape of the orbit (with an arbitrary orientation) as it would appear if viewed straight on.

A Chandra X-ray Observatory image of the Sirius star system, where the spike-like pattern is due to the support structure for the transmission grating. The bright source is Sirius B. Credit: NASA/SAO/CXC

Comparison of Sirius A and the Sun, to scale and relative surface brightness

A bust of Sopdet, Egyptian goddess of Sirius and the fertility of the Nile, syncretized with Isis and Demeter

Sirius midnight culmination at New Year 2022 local solar time

Yoonir, symbol of the universe in Serer religion

Sirius is a binary star consisting of a main-sequence star of spectral type A0 or A1, termed Sirius A, and a faint white dwarf companion of spectral type DA2, termed Sirius B. The distance between the two varies between 8.2 and 31.5 astronomical units as they orbit every 50 years.

Supernova

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Powerful and luminous explosion of a star.

SN Antikythera in galaxy cluster RXC J0949.8+1707. SN Eleanor and SN Alexander were observed in the same galaxy in 2011.

Supernova remnant SNR E0519-69.0 in the Large Magellanic Cloud

"A star set to explode", the SBW1 nebula surrounds a massive blue supergiant in the Carina Nebula.

Multi-wavelength X-ray, infrared, and optical compilation image of Kepler's supernova remnant, SN 1604

Light curves are used to classify type II-P and type II-L supernovae.

In the galaxy NGC 1365 a supernova (the bright dot slightly above the galactic center) rapidly brightens, then fades more slowly.

The layers of a massive, evolved star just before core collapse (not to scale)

Supernova types by initial mass-metallicity

Within a massive, evolved star (a) the onion-layered shells of elements undergo fusion, forming an iron core (b) that reaches Chandrasekhar-mass and starts to collapse. The inner part of the core is compressed into neutrons (c), causing infalling material to bounce (d) and form an outward-propagating shock front (red). The shock starts to stall (e), but it is re-invigorated by a process that may include neutrino interaction. The surrounding material is blasted away (f), leaving only a degenerate remnant.

The atypical subluminous type II SN 1997D

SN 2008D, a type Ib supernova at the far upper end of the galaxy, shown in X-ray (left) and visible light (right)

Messier 61 with supernova SN2020jfo, taken by an amateur astronomer in 2020

The pulsar in the Crab Nebula is travelling at 375 km/s relative to the nebula.

The radioactive decays of nickel-56 and cobalt-56 that produce a supernova visible light curve

Isolated neutron star in the Small Magellanic Cloud

Periodic table showing the source of each element in the interstellar medium

Supernova remnant N 63A lies within a clumpy region of gas and dust in the Large Magellanic Cloud

The nebula around Wolf–Rayet star WR124, which is located at a distance of about 21,000 light-years

Possible causes are an accumulation of material from a binary companion through accretion, or a stellar merger.

Double star

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Pair of stars that appear close to each other as viewed from Earth, especially with the aid of optical telescopes.

Artist's impression of the discs around the young stars HK Tauri A and B.

This occurs because the pair either forms a binary star (i.e. a binary system of stars in mutual orbit, gravitationally bound to each other) or is an optical double, a chance line-of-sight alignment of two stars at different distances from the observer.

A three-dimensional representation of the Roche potential in a binary star with a mass ratio of 2, in the co-rotating frame. The droplet-shaped figures in the equipotential plot at the bottom of the figure define what are considered the Roche lobes of the stars., and are the Lagrangian points where forces (considered in the rotating frame) cancel out. Mass can flow through the saddle point from one star to its companion, if the star fills its Roche lobe.

Roche lobe

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The Roche lobe is the region around a star in a binary system within which orbiting material is gravitationally bound to that star.

Alpha Centauri

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Gravitationally bound system of the closest stars and planets to the Solar System at 4.37 light-years from the Sun.

Apparent and true orbits of Alpha Centauri. The A component is held stationary, and the relative orbital motion of the B component is shown. The apparent orbit (thin ellipse) is the shape of the orbit as seen by an observer on Earth. The true orbit is the shape of the orbit viewed perpendicular to the plane of the orbital motion. According to the radial velocity versus time, the radial separation of A and B along the line of sight had reached a maximum in 2007, with B being further from Earth than A. The orbit is divided here into 80 points: each step refers to a timestep of approx. 0.99888 years or 364.84 days.

The relative sizes and colours of stars in the Alpha Centauri system, compared to the Sun

Relative positions of Sun, Alpha Centauri AB and Proxima Centauri. Grey dot is projection of Proxima Centauri, located at the same distance as Alpha Centauri AB.

The two bright stars at the lower right are Alpha (right) and Beta Centauri (left, above antenna). A line drawn through them points to the four bright stars of the Southern Cross, just to the right of the dome of the Danish 1.54 m telescope at La Silla Observatory in Chile.

$Alpha Centauri AB taken in daylight by holding a Canon Powershot S100 in line with the eyepiece of a 110-mm refractor. The photo is one of the best frames of a video. The double star is clearly visible.$