SDSS J141624.08+134826.7 (abbreviated SDSS J1416+1348) is a nearby wide binary system of two brown dwarfs, located in constellation Boötes. The system consists of L-type component A and T-type component B.

Discovery Component A was discovered in late 2009Date of arXiv preprint. The articles was published in journals in early 2010. from a search of Sloan Digital Sky Survey (SDSS) Data Release 7, an astronomical survey conducted at Apache Point Observatory in New Mexico, United States. It has two discovery papers: Bowler et al., 2009 and Schmidt et al., 2009.

Component B was discovered in early 2010 from UKIDSS Large Area Survey (ULAS) Data Release 5 & 6, an astronomical survey conducted on the United Kingdom Infrared Telescope (UKIRT) on Mauna Kea in Hawaii. It has also two discovery papers: Burningham et al., 2010 and Scholz, 2010. Burningham et al. discovered the whole system (independently of Bowler et al. and Schmidt et al.) by cross-matching the ULAS DR5 against SDSS DR7, and Scholz discovered component B by inspecting the UKIDSS finding charts around already found component A.

Distance

In 2012 was published the first relatively precise parallax of SDSS J1416+1348, measured at the Canada-France-Hawaii Telescope under The Hawaii Infrared Parallax Program: 109.9 ± 1.8 mas, corresponding to a distance 9.10 ± 0.15 pc (29.7 ± 0.5 ly). (Although, two parallaxes with large errors was previously published by Bowler et al. and Scholz).

+ SDSS J1416+1348 distance estimates Source Parallax, mas Distance, pc Distance, ly Ref. Bowler et al., 2009 107 ± 34Relative parallax. 9.3 30.5 Bowler et al., 2009 8.4 ± 1.9 27.4 ± 6.2 Schmidt et al., 2009 8.0 ± 1.6 26.1 ± 5.2 Burningham et al., 2010 5–15 16–49 Scholz, 2010 7.9 ± 1.7 25.8 ± 5.5 Burgasser et al., 2010 10.6 34.6 Cushing et al., 2010 9.7 ± 0.1The error does not include any errors in temperature and surface gravity and therefore is actually larger. 31.6 ± 0.3 The Hawaii Infrared Parallax Program(Dupuy & Liu, 2012) 109.9 ± 1.8 9.10 ± 0.15 29.7 ± 0.5

Non-trigonometric distance estimates are marked in italic. The best estimate is marked in bold.

Space motion SDSS J1416+1348 has proper motion 165 mas·yr−1 with position angle 32 degrees, indicating motion in north-east direction on the sky. Corresponding right ascension and declination components of proper motion are 88.0 ± 2.8 mas/yr and 139.9 ± 1.3 mas/yr, respectively. At distance 29.7 ly (assuming parallax 109.0 ± 1.8 mas), corresponding tangential velocity is 7.1 km/s. Radial velocity of SDSS J1416+1348 is -42.2 ± 5.1 km/s. (Negative radial velocity value indicates that SDSS J1416+1348 is now approaching to us). Total velocity of SDSS J1416+1348 relatively to Solar system is 42.8 km/s.

SDSS J1416+1348 space motions estimates Source μ,mas/yr P. A.,° μRA,mas/yr μDEC,mas/yr Vtan,km/sAssuming parallax 109.9 ± 1.8 mas. Vr,km/s Ref. Bowler et al., 2009 151 ± 8 33 ± 4 82 127 6.5 –38 ± 10 Schmidt et al., 2009 165 32 88.0 ± 2.8 139.9 ± 1.3 7.1 -42.2 ± 5.1 Scholz, 2010 163 32 86.2 ± 2.6 138.8 ± 2.6 7.1 SIMBAD 165 32 88 ± 3 140 ± 2 7.1 -87 ± 33 Dupuy & Liu, 2012 161.3 ± 2.8 36.1 ± 1.2 95.1 ± 3.0 130.3 ± 3.0 7.1

The most accurate estimates are marked in bold.

Space motion of SDSS J1416+1348 indicates that it is member of Galactic thin disk population.

Solar encounter Since SDSS J1416+1348 moves much faster in radial direction than in tangential direction, and radial velocity is negative, this brown dwarf system should pass the Solar System in the future at a much smaller distance than today's distance. Proper motion and radial velocity values from Schmidt et al., 2009 and parallax from Dupuy & Liu, 2012, assuming motion with constant velocity along straight line, yield minimal distance 4.9 ly circa year 207100.

Solar encounter chronology, assuming motion with constant velocity in a straight line relative to the Solar System:Actually, galactic orbits may be considered as approximately straight lines only on a scale much smaller than theirs sizes.

Date Distance,ly Constellation Note 759300 BC 137.96 Virgo/Boötes transition to constellation Boötes 493000 BC 100 Boötes approach to a distance of 100 ly 141600 BC 50 Boötes approach to a distance of 50 ly 300 BC 30 Boötes approach to a distance of 30 ly 2000 29.68 Boötes near present time 71300 20 Boötes approach to a distance of 20 ly 107900 15 Boötes approach to a distance of 15 ly 146200 10 Boötes approach to a distance of 10 ly 162900 8.01 Boötes/Corona Borealis transition to constellation Corona Borealis 168000 7.46 Corona Borealis/Boötes transition to constellation Boötes 170600 7.18 Boötes/Hercules transition to constellation Hercules 186500 5.76 Hercules/Draco transition to constellation Draco 202000 5 Draco approach to a distance of 5 ly 203600 4.97 Draco/Cygnus transition to constellation Cygnus 207100 4.95 Cygnus minimal distance 207600 4.95 Cygnus/Cepheus transition to constellation Cepheus 212200 5 Cepheus removal to a distance of 5 ly 212800 5.01 Cepheus/Cygnus transition to constellation Cygnus 215300 5.08 Cygnus /Cepheus transition to constellation Cepheus 215600 5.09 Cepheus/Lacerta transition to constellation Lacerta 222500 5.41 Lacerta/Andromeda transition to constellation Andromeda 262300 9.3 Andromeda/Pisces transition to constellation Pisces 268000 10 Pisces removal to a distance of 10 ly 306400 15 Pisces removal to a distance of 15 ly 343000 20 Pisces removal to a distance of 20 ly 410500 29.44 Pisces/Cetus transition to constellation Cetus 414500 30 Cetus removal to a distance of 30 ly 507000 43.07 Cetus transition to southern hemisphere 555900 50 Cetus removal to a distance of 50 ly 907200 100 Cetus removal to a distance of 100 ly

System's properties SDSS J1416+1348 is an old system (age estimates: >0.8 Gyr, ~10 Gyr, ~5 Gyr, 2–10 Gyr, >3.2 Gyr), and, probably, possesses low metallicity. Its two components are separated at angular distance 9.81 arcsec, corresponding to a projected separation 89.3 ± 1.5 a. u. The system's orbit semi-major axis estimate is 104 a. u.

Component A The primary (brighter) component (SDSS J141624.08+134826.7 is its full designation; also known as SDSS J1416+13A) is a brown dwarf of spectral type sdL7, or L6, or L5, or d/sdL7. It has unusually blue near-infrared J−KS color. According to Cushing et al. 2010, its peculiar spectrum is primarily a result of thin condensate clouds, and also vertical mixing occurs in its atmosphere. However, in Burgasser et al., 2010 it was suggested that its (as well as component's B) peculiarities arise from age or metallicity, rather than cloud properties alone (since both A and B components have common peculiarities).

Component B The secondary (fainter) component (ULAS J141623.94+134836.3, abbreviated to ULAS J1416+1348, also known as SDSS J1416+13B) is a brown dwarf of spectral type T7.5, or T7.5p. It has unusually extremely blue near-infrared color H−K, very red optical-to-near-infrared color (z−Y > +2.3 and z−J > +3.1), and extremely red color H−[4.5] = 4.86 ± 0.04 (it was suggested, that the latter may be explained by presence of a cooler unresolved companion to SDSS J1416+13B). Also, its spectrum indicates high surface gravity and/or subsolar metallicity.

See also List of star systems within 25–30 light-years 2M1101AB UScoCTIO 108 Oph 162225-240515 Binary brown dwarfs

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