SDSS J1416+1348


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 2009 from a search of Sloan Digital Sky Survey 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 Data Release 5 & 6, an astronomical survey conducted on the United Kingdom Infrared Telescope 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 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..
SourceParallax, masDistance, pcDistance, lyRef.
Bowler et al., 2009107 ± 349.330.5
Bowler et al., 20098.4 ± 1.927.4 ± 6.2
Schmidt et al., 20098.0 ± 1.626.1 ± 5.2
Burningham et al., 20105–1516–49
Scholz, 20107.9 ± 1.725.8 ± 5.5
Burgasser et al., 201010.634.6
Cushing et al., 20109.7 ± 0.131.6 ± 0.3
The Hawaii Infrared Parallax Program
109.9 ± 1.89.10 ± 0.1529.7 ± 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, corresponding tangential velocity is 7.1 km/s. Radial velocity of SDSS J1416+1348 is -42.2 ± 5.1 km/s.. Total velocity of SDSS J1416+1348 relatively to Solar system is 42.8 km/s.
SDSS J1416+1348 space motions estimates
Sourceμ,
mas/yr		P. A.,
°		μRA,
mas/yr		μDEC,
mas/yr		Vtan,
km/s		Vr,
km/s		Ref.
Bowler et al., 2009151 ± 833 ± 4821276.5–38 ± 10
Schmidt et al., 20091653288.0 ± 2.8139.9 ± 1.37.1-42.2 ± 5.1
Scholz, 20101633286.2 ± 2.6138.8 ± 2.67.1
SIMBAD1653288 ± 3140 ± 27.1-87 ± 33
Dupuy & Liu, 2012161.3 ± 2.836.1 ± 1.295.1 ± 3.0130.3 ± 3.07.1

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 Solar system in future at 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 relatively Solar system:
DateDistance,
ly		ConstellationNote
759300 BC137.96Virgo/Boötestransition to constellation Boötes
493000 BC100Boötesapproach to a distance of 100 ly
141600 BC50Boötesapproach to a distance of 50 ly
300 BC30Boötesapproach to a distance of 30 ly
200029.68Boötesnear present time
7130020Boötesapproach to a distance of 20 ly
10790015Boötesapproach to a distance of 15 ly
14620010Boötesapproach to a distance of 10 ly
1629008.01Boötes/Corona Borealistransition to constellation Corona Borealis
1680007.46Corona Borealis/Boötestransition to constellation Boötes
1706007.18Boötes/Herculestransition to constellation Hercules
1865005.76Hercules/Dracotransition to constellation Draco
2020005Dracoapproach to a distance of 5 ly
2036004.97Draco/Cygnustransition to constellation Cygnus
2071004.95Cygnusminimal distance
2076004.95Cygnus/Cepheustransition to constellation Cepheus
2122005Cepheusremoval to a distance of 5 ly
2128005.01Cepheus/Cygnustransition to constellation Cygnus
2153005.08Cygnus /Cepheustransition to constellation Cepheus
2156005.09Cepheus/Lacertatransition to constellation Lacerta
2225005.41Lacerta/Andromedatransition to constellation Andromeda
2623009.3Andromeda/Piscestransition to constellation Pisces
26800010Piscesremoval to a distance of 10 ly
30640015Piscesremoval to a distance of 15 ly
34300020Piscesremoval to a distance of 20 ly
41050029.44Pisces/Cetustransition to constellation Cetus
41450030Cetusremoval to a distance of 30 ly
50700043.07Cetustransition to southern hemisphere
55590050Cetusremoval to a distance of 50 ly
907200100Cetusremoval to a distance of 100 ly

System's properties

SDSS J1416+1348 is an old system, 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 component 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 peculiarities arise from age or metallicity, rather than cloud properties alone.

Component B

The secondary component 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, and extremely red color H− = 4.86 ± 0.04. Also, its spectrum indicates high surface gravity and/or subsolar metallicity.