| Exoplanetary Scratchpad|
Systems With Multiple PlanetsEdit
Systems With Hot GiantsEdit
Has planet TrES-3, the most massive transiting Very Hot Jupiter planet. Planet has one of the first two ground-detected atmospheres. A large ground-based telescope method of observation was pioneered on this planet.
AC+27°28217 is best known as Gliese 436. The second known red dwarf planetary system. Contains one of the first Neptunians discovered and a few potential planets. The star is about half the sun's mass. It is over 11 Billion years old and may be a part of the old disk of the Milky Way. Planet b temporarily later found to be the smallest exoplanet (about Uranus' diameter, though over 50% its mass) known to transit its host star and is currently the nearest (33 ly). Its temperature (712K) was measured to be higher than what it would be purely from radiation (520K), perhaps due to a greenhouse effect, somewhat higher than Venus. It was originally thought to have a layer of "hot ice", water solidified due to high pressures. It turned out that it was larger than thought and hot ice was not needed. It could still be a rocky super-Earth. It was later found to have a remarkably low levels of Methane and high levels of Carbon Monoxide for its 800K temperature. Possible explanations include Methane being changed into hydrocarbon polymers due to its star's ultraviolet radiation, CO being drafted upwards with winds, or observational defects. Later, due to lack of detection of chemical signatures through the backlit atmosphere, it was concluded that high altitude clouds, perhaps made of potassium chloride or zink sulphide dust, were blocking the detection. This could be the first detection of clouds of a Neptunian. An alternate theory is that the atmosphere is filled with heavy compounds, such as water, carbond dioxide, which would compress the atmosphere and make it difficult to detect. After detection of a huge comet-like tail of Hydrogen trailing and wrapping around its orbit led to the most recent theory that it lost its Hydrogen to uv radiation and was left with a Helium dominated atmosphere with plenty of CO instead of CH4. It's significant eccentricity suggests a possible neighboring planet. Planet c was announced to be the smallest known exoplanet (1.5 Earth's diameter), but was later retracted because variations in transit timing of the first planet did not occur and the proposed orbit would be unstable. It is still thought that a second planet of some kind is possible in the system. Candidate UCF-1.01 was detected by a student in the UCF's astronomy department using the Spitzer Space Telescope. It is about 2/3 Earth's diameter (smaller than all but one confirmed exoplanet), orbits around its star in 1.5 days, and at 1000F may be a lava world without an atmosphere. UCF-1.02 also may exist. Both are thought to be about 1/3 as massive as the Earth, but are too small to get their mass measured and thus too small to be confirmed with present technology.
A binary star in Velpulca (the "little fox") consisting of an Orange Dwarf star A and a Red Dwarf B (discovered shortly after planet Ab found and orbiting perpendicular to that planet's orbit and later detected in x-rays) orbiting 216 AU away. Planet Ab (the first nearby Very Hot Jupiter, originally thought to be inflated, is 13% larger and more massive than Jupiter) is the nearest transiting Hot Jupiter (62.9 ly). This is the first exoplanet to have its temperature mapped and was nicknamed Bull's Eye for its hot spot that is significantly offset from the starward pole. 5 years later, it later became the first world to have its thermal emissions mapped in both longtitude and latitude, confirming the hot spot was near the equator. Fast winds are thought to make the temperature of the eternal day and night sides nearly identical, which were later measured to be 2km/s when the planet became the first to have its wind and weather patterns mapped. It is also the first exoplanet for which scattered light in the upper atmosphere has been detected and the second exoplanet with water detected and first with Methane and then Carbon Dioxide detected. It later was the first exoplanet whose gasses were detected from Earth-based telescopes. It was also found to spin up its star and magnetically interact with it, causing stellar storms. Massive X-class solar flares blast off much of the planet's atmosphere and may render it undetectable. Hubble found that its atmosphere was a uniform blue haze. Blue was detected by determining which wavelengths were blocked during a transit. It was also found to rain molten glass, sideways, with 7000 km/hr winds and 1000C. It became the first exoplanet whose transit was detected in X-Rays, which revealed it had a very large extended outer atmosphere, which is losing material rapidly. The star is much more magnetically active for its age, possibly due to the planet's presence. There is speculation that it could have large planet-wide auroras. It's already-known mass was measured using an atmospheric pressure method to test its viability. By studying sodium spectra, it was determined that it gets hotter with altitude.
Systems With Debris FieldsEdit
Ran (Epsilon Eridani) is the nearest single non-red dwarf star to the Sun, also known as HD 195019, Gl 144, and HR 1084. It is a member of the Ursa Major star association and close encounters to other stars is relatively common. One of the first stars found to have a dust disk, with several potential planets suspected in the gaps early on, and later on of the earliest nearest system with confirmed planets. Has an inner asteroid belt at 3 AU, Jovian planet AEger at 3.4 AU, outer asteroid belt at 20 AU, and Kuiper Belt at 35-100 AU. A planet is proposed to be just outside the outer asteroid belt, and another just before the Kuiper belt.Because the star is very chromospherically active, doubts were cast on planet's b's existence. Hubble then confirmed its existence with astrometrics and found to be orbiting in the plane of the dust disks, which supported the theory that planets are born from dust disks and yielded a precise mass of 1.5 MJ. The planet b was originally thought to be extremely eccentric (2-10 AU), but later discovery of the inner asteroid belt suggests it is more moderately eccentric so as not to cross the belt. It could still have high eccentricity if the outer belt was being fed with material from the outer belt though. Dinosaur-killing sized impacts would be frequent on any Earth-like planets, about once every 2 million years. One of 5 PICTURE-C targets selected for sub-orbital coronograph observation. One of the first 20 exoplanet systems allowed to be given common names by the IAU. Star is named after a Norse goddess of the seas, while the planet after her husband, god of the ocean. A common sci fi system, including the original home of Star Trek Vulcans (though this moved to 40 Eridani) and Babylon 5.
Tau Ceti is also known as HD 10700, HR 509, and Gl 71. The nearest single G-class yellow dwarf to the sun, somewhat smaller than the Sun. A popular science fiction subject and one of two targets of SETI-forerunner Project Ozma in the 1960s. Despite being somewhat older than the sun, it has an extensive asteroid and/or comet field 10-50 AU, with the bulk between 35 and 50 AU. It has about ten times as much material as the Sun. This would make life difficult. It is a metal deficient star, so it is thought less likely to host rocky planets. Traditional dopplar spectrometry has ruled out any large Jupiter sized planets at Jupiter like distances or closer in, which was thought to be good for any potentially habitable planets. Five candidate rocky super Earth planets were detected though using a new method of planetary detection. This method made predictions of the stellar "noise" activity that might obscure detection of a planet based on the long history of dopplar measurements done on this system. Deviations from this prediction pointed towards the existence of planets. Confirmation using more established methods is needed. These planets are labeled b through f as you go outward, span 0.1 AU to 1.35 AU, and get larger the further you go out (at least 2 ME to 6.6 ME). The outermost two are near the habitable zone and were originally hailed as possibly being the nearest and smallest known habitable planets. More recent modeling indicates they are not actually habitable though. Planet e is probably too close to the star and only in the HZ if generous assumptions are made. Planet f has probably only been in the habitable zone for about a billion years as a result of its star becoming hotter, which might make biosigns difficult to detect from Earth, considering it took 2 BY for biosigns to become detectable around the Earth. Since the star has a higher magnesium to silicon ratio than the Sun, these planets compositions could be quite different that the Solar System's. The lower mantles could be dominated with ferropericlase, which is not very viscious, which may make the rocks of the mantle flow easier than on Earth, affecting volcanism and tectonics. One of 5 PICTURE-C targets selected for sub-orbital coronograph observation.
Systems With Brown DwarvesEdit
Epsilon Indi is the also known as HR 8387, Gl 845, and HD 209100. Second nearest single sunlike star to the Sun. Orange dwarf with a binary brown dwarf orbiting it. The smaller of the two is the closest thing to an "extrasolar moon" found so far. The constellation "Indus" first appeared in 1603 in the Uranometria. Epsilon Indi appeared as one of the Indian's arrows in Bode's 1801 atlas, the Uranographia. The star's high proper motion was first discovered by Gill in 1882, which was improved upon by Shapley in 1923. During 1960, the star was observed for radio signals, but none was found. In 1972, it was searched for ultraviolet laser signals. It leads a Carnegie list of stars most likely to have an earth-like planet. The star's age has been controversial, at first thought to be older than the sun, then younger, then even older than originally thought, all based on studies regarding the brown dwarf's nature and the rotation rate of the star.