| Exoplanetary Scratchpad|
Types of planets and systems.
- Hot Jupiter - Hot Jupiters are also known as Roasters, Epistellar Jovians, Pegasids, or Pegasian planets. Some definitions are that they are Jupiter-sized planets with a period of about 3 days. They are planets as massive as Jupiter, but orbit extremely close to their stars. These are the easiest to detect using the Dopplar Spectrometry method and transiting method. The first discovered was 51 Pegasi, nicknamed Bellerophon. There are many sub-varieties. Many are thought to be tidally locked to their star, though not all. Some have super fast winds that transport heat from the day side to the dark side, meaning their temperatures are similar on both sides. Others have no winds and have much hotter day sides than night sides. They are thought to have formed far beyond the frost line and then migrated inward. Some are extra "puffy", with the largest being twice the diameter of Jupiter. Some interact magnetically with their stars, causing x-ray activity, star spots, or massive solar flares. Some have extended atmospheres. Some are losing mass and form a tail or ring around their system. They usually orbit in very circular paths, but are often at high inclination to the star's orbit, or even retrograde. They are among some of the best studied planets. Transits can often detect their atmospheres, measure their temperatures, color, and albedo, and detect molecules in their atmosphere. Classification is based on orbital period and mass, not other properties such as temperature. Though rare, Hot Jupiters around Red Dwarves can be much lower in temperature. Some are enveloped by their stars as they get older.
From Exoplanet Explorer
- pClass = Planetary Class = Zone Class + Mass Class
- Mass Class = Mercurian, Subterran, Terran, Superterran, Neptunian, Jovian
- Zone Class = Hot, Warm, Cold
- Composition Class = Iron, Rocky-Iron, Rocky-Water, Water-Gas, Gas
- Atmosphere Class = None, Metals-Rich, Hydrogen-Rich
- hClass = Habitability Class: hypopsychroplanet (O), psychroplanet (P), mesoplanet (M), thermoplanet (T), hyperthermoplanet (E), non-habitable (X).