KELT-1 is a F-type main-sequence star. Its surface temperature is 6518 K. It is similar to the Sun in its concentration of heavy elements, with a

metallicity In astronomy, metallicity is the abundance of elements present in an object that are heavier than hydrogen and helium. Most of the normal physical matter in the Universe is either hydrogen or helium, and astronomers use the word ''"metals"'' as a ...

Fe/H index of 0.008, but is much younger at an age of 1.75 billion years. The star is rotating very rapidly. A

red dwarf ''Red Dwarf'' is a British science fiction comedy franchise created by Rob Grant and Doug Naylor, which primarily consists of a television sitcom that aired on BBC Two between 1988 and 1999, and on Dave since 2009, gaining a cult following. T ...

stellar companion at a projected separation of 154 AU was detected in 2012, simultaneously with a planetary companion.

Planetary system

The star was found to be orbited by a low-mass

brown dwarf Brown dwarfs (also called failed stars) are substellar objects that are not massive enough to sustain nuclear fusion of ordinary hydrogen ( 1H) into helium in their cores, unlike a main-sequence star. Instead, they have a mass between the most ...

or giant planet in 2012. Brown dwarf/planet KELT-1b has an equilibrium temperature of 2422 K, but features a very strong contrast between measured dayside and nightside temperatures. Dayside temperature appears to be 3340 K, while nightside temperature is 1173 K. The excess dayside temperature may be an artifact arising from highly reflective (dayside albedo reaching 0.5, which is unusual for hot planets and brown dwarfs) rock-vapor clouds. Also, the brightest band is shifted eastward from the

subsolar point The subsolar point on a planet is the point at which its sun is perceived to be directly overhead (at the zenith); that is, where the sun's rays strike the planet exactly perpendicular to its surface. It can also mean the point closest to the sun ...

by 18.3°. KELT-1b's density of 22.1 g/cm³ is the highest among well characterized planets. The planetary orbit is well aligned with the equatorial plane of the star, with the misalignment angle equal to 2°. Despite the short orbital period, orbital decay of KELT-1b has not been detected as of 2018.

References

{{DEFAULTSORT:KELT-1 Andromeda (constellation) Binary stars Planetary systems with one confirmed planet Planetary transit variables F-type main-sequence stars J00012691+3923017 Brown dwarfs TIC objects

Planetary system

See also

References