HOME

TheInfoList



Click Here for Items Related To - EPIC 201563164
OR:
EPIC 201563164 on:   [Wikipedia]   [Google]   [Amazon]

WD 1145+017 (also known as EPIC 201563164) is a
white dwarf A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to the Sun's, while its volume is comparable to the Earth's. A white dwarf's faint luminosity comes ...
approximately from
Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surf ...
in the constellation of
Virgo Virgo may refer to: * Virgo (astrology), the sixth astrological sign of the zodiac * Virgo (constellation), a constellation * Virgo Cluster, a cluster of galaxies in the constellation Virgo * Virgo Stellar Stream, remains of a dwarf galaxy *Virgo ...
. It is the first white dwarf to be observed with a transiting
planetary-mass object A planetary-mass object (PMO), planemo, or planetary body is by geophysical definition of celestial objects any celestial object massive enough to achieve hydrostatic equilibrium (to be rounded under its own gravity), but not enough to sustain ...
orbiting it.


Stellar characteristics

The white dwarf has a mass of 0.6 , radius of 0.02 (1.4 ) and a temperature of 15,020 K, typical for white dwarf stars. It has been a white dwarf for 224 million years. The star included strong absorption lines due to
magnesium Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ...
,
aluminium Aluminium (aluminum in AmE, American and CanE, Canadian English) is a chemical element with the Symbol (chemistry), symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately o ...
,
silicon Silicon is a chemical element with the symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic ...
,
calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar t ...
,
iron Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in ...
and
nickel Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow ...
. These elements commonly found in
rocky planets A terrestrial planet, telluric planet, or rocky planet, is a planet that is composed primarily of silicate rocks or metals. Within the Solar System, the terrestrial planets accepted by the IAU are the inner planets closest to the Sun: Mercury ...
are polluting the surface of the star, and would normally be expected to mix through the star and disappear from view after a million years. A circumstellar dust cloud and disk (likely due to disintegrating
asteroid An asteroid is a minor planet of the Solar System#Inner solar system, inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic o ...
s, located at 97 to 103 R_wd, and emitting thermal IR radiation) surrounds the star. In addition, a circumstellar gas disk (located ~ 25 to 40 R_wd, and undergoing relativistic
precession 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 o ...
with a period of ~ 5 years) surrounds the star as well. Based on recent studies and calculations, it is believed that the star initially was an early
A-type main sequence star An A-type main-sequence star (A V) or A dwarf star is a main-sequence (hydrogen-burning) star of spectral type A and luminosity class V (five). These stars have spectra defined by strong hydrogen Balmer absorption lines. They measure between 1 ...
with a mass of about 2.46 , remaining so for an estimated 550 million years. Afterwards, following the exhaustion of hydrogen within its core, it evolved and expanded into a
red giant A red giant is a luminous giant star of low or intermediate mass (roughly 0.3–8 solar masses ()) in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius large and the surface temperature around or ...
before eventually ejecting its layers and contracting into a white dwarf, and has gradually cooled over the last 224 million years. This gives the star an estimated total age of around 774 million years. The apparent magnitude of the star, or how bright it appears from Earth's perspective, is about 17. Therefore, it is too dim to be seen with the naked eye.


Planetary system

The supposed planetesimal,
WD 1145+017 b WD 1145+017 b (also known by its EPIC designation ''EPIC 201563164.01''), is a confirmed exoplanetary object, likely rocky, orbiting around and being vaporized by the white dwarf star WD 1145+017. It was discovered by NASA's ''Kepler'' spacecraft ...
, with a 4.5 hour orbit, is being ripped apart by the star and is a remnant of the former
planetary system A planetary system is a set of gravitationally bound non-stellar objects in or out of orbit around a star or star system. Generally speaking, systems with one or more planets constitute a planetary system, although such systems may also consis ...
that the star hosted before becoming a white dwarf. It is the first observation of a planetary object being
shredded Shredding, shred, shredder, or shredders may refer to: Equipment * Industrial shredder * Paper shredder * Scrap metal shredder * Woodchipper, or tree shredder Arts, entertainment, and media Films * ''Shred'' (film), a 2008 film by David Mitchel ...
by a white dwarf. Several other large pieces have been seen in orbit as well. All the various larger pieces have orbits of 4.5 to 4.9 hours. Rocky material is raining down onto the star, and showing up in the star's spectrum. The system was detected by the
Kepler space telescope The Kepler space telescope is a disused space telescope launched by NASA in 2009 to discover Earth-sized planets orbiting other stars. Named after astronomer Johannes Kepler, the spacecraft was launched into an Earth-trailing heliocentric orbi ...
in its extended ''K2'' mission. Though the system was not a target of interest, it was within the field of view of observing sessions, and analysis of the observed data revealed the system. An excess of
infrared radiation Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...
indicates that there is a dusty disk with a temperature of . Supporting observational data, along with data from the
Chandra X-ray Observatory The Chandra X-ray Observatory (CXO), previously known as the Advanced X-ray Astrophysics Facility (AXAF), is a Flagship-class space telescope launched aboard the during STS-93 by NASA on July 23, 1999. Chandra is sensitive to X-ray sources ...
, were also found related to dust debris orbiting WD 1145+017.


Similar systems

In September 2020, astronomers reported the discovery, for the first time, of a very massive Jupiter-sized planet, named WD 1856 b, closely orbiting, every 36 hours, a tiny
white dwarf star A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to the Sun's, while its volume is comparable to the Earth's. A white dwarf's faint luminosity comes fro ...
, named
WD 1856+534 WD may refer to: Arts and entertainment * ''The Walking Dead'' (TV series) * ''White Dwarf'' (magazine) Businesses and organizations Government agencies * Royal Canadian Air Force Women's Division * War Department (United Kingdom) O ...
, a left-over remnant of an earlier much larger
sun-like star Solar-type star, solar analogs (also analogues), and solar twins are stars that are particularly similar to the Sun. The stellar classification is a hierarchy with solar twin being most like the Sun followed by solar analog and then solar-typ ...
. This WD 1856 system is similar to the WD 1145+017 system.


See also

*
Disrupted planet In astronomy, a disrupted planet is a planet or exoplanet or, perhaps on a somewhat smaller scale, a planetary-mass object, planetesimal, moon, exomoon or asteroid that has been disrupted or destroyed by a nearby or passing astronomical body or ...
*
List of stars that dim oddly This list of stars that have unusual dimming periods is a table of stars that have been observed to darken and brighten and don't appear to be eclipsing binaries or intrinsic variables. It's based on studies searching for analogs of Tabby's ...
* ZTF J0139+5245


References


External links


EPIC Catalog at MAST
* Harvard ''Center for Astrophysics''

* AstronomyNow
WD 1145+017
* AmericaSpace
WD 1145+017
{{DEFAULTSORT:WD 1145+017 White dwarfs Virgo (constellation) Hypothetical planetary systems