| Discovery | |
|---|---|
| Discovered by | Q. Konopackyet al.[1] |
| Discovery date | 2016 |
| Direct imaging | |
| Orbital characteristics[2] | |
| 19.0+5.7 −4.4 AU | |
| Eccentricity | 0.63+0.32 −0.23 |
| 71.5+35.7 −23.2 yr | |
| Inclination | 82.8+2.0 −12.5° |
| 299.5+2.5 −2.7 | |
| 207.2+34.6 −30.1 | |
| Star | HR 2562 |
| Physical characteristics | |
| 0.89+0.14 −0.27[3]RJ | |
| Mass | < 18.5[2]MJ |
| log(g) = 4.70 ± 0.32[1]m/s² | |
| Temperature | 1200 ± 100 K[1] |
HR 2562 B is a substellar companion orbiting the star HR 2562. Discovered in 2016 by a team led by Quinn M. Konopacky bydirect imaging, HR 2562 B orbits within the inner edge of HR 2562'scircumstellar disc—as of April 2023, it is one of only two knownbrown dwarfs to do so.[2] Separated by roughly 20 astronomical units (3.0×109 km) from its primary companion, HR 2562 B has drawn interest for its potential dynamical interactions with the outer circumstellar disc.
HR 2562 B was discovered using theGemini Planet Imager (GPI), which first observed the star HR 2562 in January 2016. In the initial data set, Konopacky and collaborators identified a candidate companion object. As a result, followup observations were conducted within the following month in theinfrared K1-, K2-, andJ-bands. Within the processed data set, HR 2562 B was confirmed to share a commonproper motion with HR 2562, with Konopacky and collaborators announcing its discovery in a paper published on 14 September 2016.[1]
![Image of the disk around HR 2562 with the REASONS survey[4]](/mt/?noimg=&dark=on&url=https%3a%2f%2fen.wikipedia.org%2fwiki%2fFile%3aThe_74_exocomet_belts_imaged_by_ALMA%25E2%2580%2599s_REASONS_survey%2c_showing_belts_of_all_shapes%2c_sizes_and_ages_(REASONS_comboplot_full_nonames).jpg)
HR 2562 B's parent star, HR 2562 (alternatively designated HD 50571 or HIP 32775), has a mass of1.368±0.018M☉ and a radius of1.334±0.027R☉. With an estimatedeffective temperature of 6597 ± 81K, it is amain-sequence star with thespectral typeF5V. It is located 110.92 ± 0.16light-years (34.007 ± 0.048 pc) from the Sun in the constellationPictor.[note 1] HR 2562 is not known to belong to amoving group orstellar cluster.[3][5]
As with many mid F-type stars, the age of HR 2562 is poorly constrained. Between 1999 and 2011, estimates from various teams of astronomers determined ages ranging from roughly 300 Myr to 1.6 Gyr. In 2018, a team of astronomers led by D. Mesa derived an age of450+300
−250 Myr using measurements of the star's lithium-temperature relationship.[5]
Initial observations of HR 2562 B by Konopacky and collaborators yielded a separation of 20.3 ± 0.3 AU (3.037×109 ± 45,000,000 km), placing it interior to and coplanar with the inner edge of HR 2562's observed debris disc.[1] Further observations of HR 2562 B by theAtacama Large Millimeter Array (ALMA) supported this, yielding asemi-major axis of19.0+5.7
−4.4 AU, an orbital period of71.5+35.7
−23.2 yr, and anorbital eccentricity of0.63+0.32
−0.23. With a probableorbital inclination of82.8+2.0
−12.5°, HR 2562 B's misalignment angle with the debris disc is either7+17
−4° or15+18
−5°. However, the limited coverage of observations still leaves a wide range of possible orbits; both low-eccentricity, coplanar orbits and high-eccentricity, misaligned orbits would be consistent with observation data. However, a highly misaligned orbit would significantly perturb the disc, suggesting that a low-eccentricity, coplanar solutions are likelier.[2]
Any additional companions around HR 2562 with a mass on the order of 10MJ should be visible at separations larger than 10 AU, and any companion a few times more massive than Jupiter should be visible to SPHERE's infrared dual-band spectrograph (IRDIS) instrument—thus placing mass restrictions on any additional companions.[5]
HR 2562 B's exact mass is unknown. The brown dwarf was estimated to be 29 ± 15MJ in 2021.[3] However, subsequent observations placed an upper mass limit of < 18.5MJ.[2] Its luminosity is aboutsolar luminosity.[1][note 2] Itsspectral type is L7±3.[1]
