Extragalactic planet
Encyclopedia
An extragalactic planet is a planet
that is outside the Milky Way Galaxy. Other terms used to describe these are extragalactic extrasolar planet
and extragalactic exoplanet.
gravitational lens
ing system was observed in 1996, by R. E. Schild
, in the "A" lobe of the lensed quasar. It is predicted that a 3-Earth mass planet in the lensing galaxy, YGKOW G1, caused the event. This was the first extragalactic planet announced. This however is not a repeatable observation, as it is a one time chance alignment. This predicted planet lies 4 billion light years away.
, our nearest large galactic neighbour. The lensing pattern fits a star with a smaller companion weighing just 6 or 7 times the mass of Jupiter. This suspected planet is the first announced in the Andromeda Galaxy.
is a star about 2000 light years away, well within the Milky Way and was found to have an exoplanet. However, the star is part of the Helmi stream
of stars, a leftover remnant of a small galaxy that had collided with, been torn apart, and taken in by our Milky Way over 6 billion years ago. The star is over 6 billion years old, so the star and its planet formed in an actual other galaxy, one that either orbited the Milky Way or had an unfortunately too-close pass to it. Thus the planet, HIP 13044 b
, around HIP 13044 was once an extragalactic planet. Another interesting point is the planet had almost certainly been engulfed by the star when it was in its red giant phase earlier, spending a few million years inside the star.
Planet
A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...
that is outside the Milky Way Galaxy. Other terms used to describe these are extragalactic extrasolar planet
Extrasolar planet
An extrasolar planet, or exoplanet, is a planet outside the Solar System. A total of such planets have been identified as of . It is now known that a substantial fraction of stars have planets, including perhaps half of all Sun-like stars...
and extragalactic exoplanet.
Twin Quasar related planet
A microlensing event in the Twin QuasarTwin Quasar
The Twin Quasar , also known as SBS 0957+561, or TXS 0957+561 , was the first identified gravitationally lensed object.-Quasar:...
gravitational lens
Gravitational lens
A gravitational lens refers to a distribution of matter between a distant source and an observer, that is capable of bending the light from the source, as it travels towards the observer...
ing system was observed in 1996, by R. E. Schild
R. E. Schild
Rudolph E. Schild, PhD is an astrophysicist at the Harvard-Smithsonian Center for Astrophysics. He has authored or contributed to over two hundred and fifty papers. He is married to mezzo soprano Jane Struss, who teaches voice at Longy School of Music....
, in the "A" lobe of the lensed quasar. It is predicted that a 3-Earth mass planet in the lensing galaxy, YGKOW G1, caused the event. This was the first extragalactic planet announced. This however is not a repeatable observation, as it is a one time chance alignment. This predicted planet lies 4 billion light years away.
Andromeda Galaxy planets
A team of scientists has used gravitational microlensing to come up with a tentative detection of an extragalactic exoplanet in AndromedaAndromeda Galaxy
The Andromeda Galaxy is a spiral galaxy approximately 2.5 million light-years from Earth in the constellation Andromeda. It is also known as Messier 31, M31, or NGC 224, and is often referred to as the Great Andromeda Nebula in older texts. Andromeda is the nearest spiral galaxy to the...
, our nearest large galactic neighbour. The lensing pattern fits a star with a smaller companion weighing just 6 or 7 times the mass of Jupiter. This suspected planet is the first announced in the Andromeda Galaxy.
HIP 13044
HIP 13044HIP 13044
HIP 13044 is a red horizontal branch star about 2,300 light years away from the Earth in the constellation Fornax. The star is part of the Helmi stream, a former dwarf galaxy that merged with the Milky Way between six and nine billion years ago. As a result, HIP 13044 circles the galactic center...
is a star about 2000 light years away, well within the Milky Way and was found to have an exoplanet. However, the star is part of the Helmi stream
Helmi stream
The Helmi stream is a stellar stream of the Milky Way Galaxy. It started as a dwarf galaxy, now absorbed by the Milky Way as a stream. It was discovered in 1999, is formed of old stars deficient in heavy elements and has a mass of 10 to 100 million solar masses...
of stars, a leftover remnant of a small galaxy that had collided with, been torn apart, and taken in by our Milky Way over 6 billion years ago. The star is over 6 billion years old, so the star and its planet formed in an actual other galaxy, one that either orbited the Milky Way or had an unfortunately too-close pass to it. Thus the planet, HIP 13044 b
HIP 13044 b
HIP 13044 b is a Jupiter-like extrasolar planet orbiting the old and metal-poor red giant star HIP 13044, which is situated approximately 2,000 light years away from the Earth in the constellation Fornax. Its discovery was announced on November 18, 2010 after observations using the FEROS...
, around HIP 13044 was once an extragalactic planet. Another interesting point is the planet had almost certainly been engulfed by the star when it was in its red giant phase earlier, spending a few million years inside the star.
See also
- Solar System planets
- Exoplanet
- PlanetPlanetA planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...