Exoplanetary Scratchpad

[SysBP Img]

A moving group about 100 to 300 Million Years Old.

Castor Moving Group Web PagesEdit

Member Star SystemsEdit

  • Fomalhaut System - Fomalhaut is also known as Piscis Austrini, 24 Piscis Austrini, Gl 881, HD 216956, and HR 8728. A triple star, the second brightest star known to have exoplanets. Star A is a white main sequence star about twice the Sun's mass and somewhat less than twice its radius. It was originally thought to be about 200 million years old, but now thought to be 400 MYO, and will turn into a giant in about a billion years. Its dust disk is observed in unprecedented detail. It appears reminiscent of the "Eye of Sauron" from the Lord of the Rings films. A planet suspected of causing a sharp gap in the ring was suspected and imaged, becoming the first visually detected and the first planet since Neptune to be predicted prior to its discovery. The planet, Dagon, orbits about 115 AU and is between Neptune and 3x Jupiter's mass in an eccentric orbit. Planet b was shown to deviate slightly from its predicted path, stirring up some controversy about the planets' existence. The Hubble instrument that detected it is damaged and will not be fixed, making it unobservable for a time. Later analysis of old Hubble data confirmed its existence. Material surrounding the planet has been imaged, rather than the planet itself, which its discoverers admit takes it off the directly imaged list. The planet is hurdling outward from the star in a highly elongated path and will encounter the inner edge of the outer belt in 2032, where icy debris will smash into its atmosphere (unless its orbit is highly inclined). No heat has been detected from the planet, which suggests it is sub-Jovian in mass and could be as small as Pluto, though this could be explained by dissipation from surrounding dust. Evidence for another planet "slicing" through the dust disk was also found, and it may have been responsible for planet b's elliptical orbit. The shape of the ring was put into focus by ALMA, 140 AU out, 16 AU wide, and 1/7th AU thick, placing limits on proposed shepherding exoplanets and showing them to be quite small (a couple times larger than Mars), perhaps why they weren't detected visually. Mapping by ALMA was completed later on and shows the first "apocenter glow", where dust particles clump around slower moving and further out parts of their elliptical orbit. Some proposed inner planets via effects of debris disk could be better interpreted as gas produced effects. The ring is believed to be continuously replenished by cometary collisions occurring every day. An estimated 260 Billion to 83 Trillion comets could exist in it, equivalent to what is in the Sun's Oort Cloud. Star B, an orange dwarf 0.91 ly away has no known disk. Star C, a recently identified Red Dwarf member of the system, located extremely far from the primary (2.5 ly), was also found to have its own disk. Previous interactions may have tilted Star A's disk. The star is a part of the Castor Moving Group. One of the first 20 exoplanet systems allowed to be given common names by the IAU. The planet is named after a half fish Semitic god.
  • Castor System - Principle member of the Castor Moving Group. Contains one of the few known red dwarf eclipsing binary stars known as YY Geminorum.
  • Vega System - Vega is also known as Alpha Lyrae, HR 7001, HD 172167, and Gl 721. It is the fifth brightest star in the night sky the second brightest star visible from the Northern hemisphere, and brightest star in the Northern Summer. It is part of the Summer Triangle. It was the first star to be photographed in 1850. It is a slightly bluish star (A0) with about 2.15 times the sun's mass and 2.7 its diameter. It was at first estimated to be about 200 Million Years old, but now thought to be closer to 700. It was found to be rotating so fast that the equator bulges significantly (23%) and is cooler at its poles. Nearby star with one of the first detected circumstellar disks. The star is pointed nearly pole-on from the Earth, so it is ideal for the observation of dust disks. There have been many studies suggesting planets are responsible for features found in the disk. Two bright "clumps" of dust were identified and thought to be due to the gravitational effects of an eccentric planet's orbit. It was surmised that this disk was caused by a collision between Pluto sized objects. A distinct asteroid belt and kuiper belt at distance scales that dwarf our Solar Systems was found to exist, which suggest outer planets clearing out the space in between. These planets cannot be detected at the present, but could be detected by the James Webb Space Telescope. One of 5 PICTURE-C targets selected for sub-orbital coronograph observation.
  • Alpha Cephei System - Member of the Castor Moving Group.
  • Alpha Librae System - Principle member of the Castor Moving Group.
  • Alpha 2 Librae System - Member of the Castor Moving Group.
  • TW Piscis Austrini System - TW PsA is also known as Gl 879, HR 8721, HD 216803, and CD-32°17321. An orange dwarf flare star and a BY Draconis variable, one of the larger such stars. Less than a light year from Fomalhaut (57,000 AU), and possibly gravitationally bound to it in a cluster or stellar association in the Castor Moving Group. They were found to share a common proper motion and in 2012 it was found to be consistent with a binary syste. About 200 Million Years old, along with the rest of the group. Visible to some humans with the naked eye.
  • DX Cancri System - DX Cancri is also known as G 051-015, GJ 1111 and informally Proxima Cancri. It is a nearby red dwarf flare star designated. A "spectacular" flare was detected in 2006. A search for a dust disk was undertaken, but none was found. This is thought to be a member of the Castor Moving Group. Its proper motion may first have been noticed by William Luyten.
  • Zeta Leporis System - A massive young star around which the first direct evidence for an asteroid belt were detected in 2001. A part of the Castor Moving Group.
  • HD 51825 System - Member of the Castor Moving Group.
  • Psi Velorum System - Member of the Castor Moving Group.
  • Gliese 351 System - Member of the Castor Moving Group.
  • Gliese 426 System - Member of the Castor Moving Group.
  • GJ 408 System - Member of the Castor Moving Group.
  • GJ 4247 System - Member of the Castor Moving Group.
  • HD 117934 System - Member of the Castor Moving Group.
  • HD 119124 System - Member of the Castor Moving Group.
  • HD 162283 System - Member of the Castor Moving Group.
  • HD 181321 System - Member of the Castor Moving Group.
  • Gliese 842.2 System - Member of the Castor Moving Group.
  • Gliese 896 System - Member of the Castor Moving Group.
  • Kappa Phoenicis System - Member of the Castor Moving Group.

Castor Moving Group In the NewsEdit

Sample (Year)Edit

See AlsoEdit

Ad blocker interference detected!

Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.