Oph 162225-240515
Encyclopedia
Oph 162225-240515, often abbreviated Oph1622, is a pair of brown dwarf
s that have been reported as orbiting each other. The bodies are located in the constellation
Ophiuchus
and are about 400 light years away. Mass estimates of the two objects are uncertain, but they are probably each higher than the brown-dwarf/planet
dividing line of 13 Jupiter
masses: estimate the mass of the primary, designated Oph1622A as 12–21 times that of Jupiter and 9–20 Jupiter masses for the less massive Oph1622B, while assign values of 57 and 20 Jupiter masses. Oph1622B is located 1.94 arcseconds away from Oph1622A, at a position angle
of 182°. The pair are estimated to be around 5 million years old.
Announced in the 2006-08-04 issue of Science
by Ray Jayawardhana
and Valentin D. Ivanov
, the objects were discovered using telescopes of the European Southern Observatory
's "New Technology Telescope" in La Silla, Chile
. The masses were originally reported to be lower, at 14 and 7 Jupiter masses, which would have made the smaller object a planetary-mass object, or "planemo". The system was announced as the first reported binary system of objects this small. However later observations revised the masses upward, and both are above the 13 Jupiter mass dividing line between planet
s and brown dwarfs.
The distance between the two is approximately 240 Astronomical Unit
s—a distance so great that Space.com
wrote that "their connection is so tenuous ... that a passing star or brown dwarf could permanently separate the two objects." As such, the discovery was reported as casting doubt on the theory that such free-floating planet-like objects have been ejected from a stellar system, such an event being too violent to leave them in orbit around each other.
Brown dwarf
Brown dwarfs are sub-stellar objects which are too low in mass to sustain hydrogen-1 fusion reactions in their cores, which is characteristic of stars on the main sequence. Brown dwarfs have fully convective surfaces and interiors, with no chemical differentiation by depth...
s that have been reported as orbiting each other. The bodies are located in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
Ophiuchus
Ophiuchus
Ophiuchus is a large constellation located around the celestial equator. Its name is from the Greek "serpent-bearer", and it is commonly represented as a man grasping the snake that is represented by the constellation Serpens. Ophiuchus was one of the 48 constellations listed by the 2nd-century...
and are about 400 light years away. Mass estimates of the two objects are uncertain, but they are probably each higher than the brown-dwarf/planet
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,...
dividing line of 13 Jupiter
Jupiter
Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...
masses: estimate the mass of the primary, designated Oph1622A as 12–21 times that of Jupiter and 9–20 Jupiter masses for the less massive Oph1622B, while assign values of 57 and 20 Jupiter masses. Oph1622B is located 1.94 arcseconds away from Oph1622A, at a position angle
Position angle
Position angle, usually abbreviated PA, is a measurement derived from observing visual binary stars. It is defined as the angular offset in degrees of the secondary star to the primary, relative to the north celestial pole....
of 182°. The pair are estimated to be around 5 million years old.
Announced in the 2006-08-04 issue of Science
Science (journal)
Science is the academic journal of the American Association for the Advancement of Science and is one of the world's top scientific journals....
by Ray Jayawardhana
Ray Jayawardhana
Ray Jayawardhana is an astronomer at the University of Toronto, where he holds the Canada Research Chair in Observational Astrophysics, and an award-winning science writer...
and Valentin D. Ivanov
Valentin D. Ivanov
Valentin D. Ivanov is a Bulgarian astronomer, currently working in the European Southern Observatory, mainly at the Paranal site. Among his primary research areas are the dynamics of star clusters, formation of stars, brown dwarfs, and exoplanets around such objects.Valentin Ivanov and Ray...
, the objects were discovered using telescopes of the European Southern Observatory
European Southern Observatory
The European Southern Observatory is an intergovernmental research organisation for astronomy, supported by fifteen countries...
's "New Technology Telescope" in La Silla, Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
. The masses were originally reported to be lower, at 14 and 7 Jupiter masses, which would have made the smaller object a planetary-mass object, or "planemo". The system was announced as the first reported binary system of objects this small. However later observations revised the masses upward, and both are above the 13 Jupiter mass dividing line between planet
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,...
s and brown dwarfs.
The distance between the two is approximately 240 Astronomical Unit
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
s—a distance so great that Space.com
Space.com
Space.com is a space and astronomy news website. Its stories are often syndicated to other media outlets, including CNN, MSNBC, Yahoo!, and USA Today.Space.com was founded by former CNN anchor Lou Dobbs and Rich Zahradnik, in July 1999...
wrote that "their connection is so tenuous ... that a passing star or brown dwarf could permanently separate the two objects." As such, the discovery was reported as casting doubt on the theory that such free-floating planet-like objects have been ejected from a stellar system, such an event being too violent to leave them in orbit around each other.
External links
- http://www.sciencedaily.com/releases/2006/08/060804084105.htm
- http://www.spacedaily.com/reports/Astronomers_Discover_Twin_Planemos_999.html