WISE 1217+1626


WISEPC J121756.91+162640.2 is a binary brown dwarf system of spectral classes T9 + Y0, located in constellation Coma Berenices at approximately 33 light-years from Earth.

History of observations

Discovery

WISE 1217+1626 A was discovered in 2011 by J. Davy Kirkpatrick et al. from data, collected by Wide-field Infrared Survey Explorer Earth-orbiting satellite — NASA infrared-wavelength 40 cm space telescope, which mission lasted from December 2009 to February 2011. In 2011 Kirkpatrick et al. published a paper in The Astrophysical Journal Supplement, where they presented discovery of 98 new found by WISE brown dwarf systems with components of spectral types M, L, T and Y, among which also was WISE 1217+1626.

Initial estimate of spectral type

Initial estimate of WISE 1217+1626' spectral type was T9.

Discovery of component B

WISE 1217+1626 B was discovered in 2012 by Liu et al. with laser guide star adaptive optics system of the 10-m Keck II Telescope on Mauna Kea, Hawaii, using infrared camera NIRC2. On 2012 April 1 Liu et al. observed WISE J1217+1626AB using the near-IR camera NIRI on the Gemini-North 8.1-m telescope on Mauna Kea, Hawaii and the binary was marginally resolved. On 12 April 2012 they obtained resolved spectroscopy of WISE J1217+1626AB with the near-IR spectrograph NIRSPEC again on the Keck II Telescope. In 2012 Liu et al. published a paper in The Astrophysical Journal where they presented results of observations with Keck II LGS-AO of three brown dwarf binary systems, binarity of one of which was known before, and binarity of the other two, including WISE 1217+1626, was first presented in this paper.

Distance

Currently the most accurate distance estimate of WISE 1217+1626 is a trigonometric parallax, measured using Spitzer Space Telescope and published in 2013 by Trent Dupuy and Adam Kraus: 0.099 ± 0.016 arcsec, corresponding to a distance 10.1 pc, or 32.9 ly. In the estimates made before discovery of the component's B by Liu et al. in 2012 the binarity is not taken into account.
WISE 1217+1626 distance estimates
SourceParallax, masDistance, pcDistance, lyRef.
Kirkpatrick et al.
~6.7~21.9
Kirkpatrick et al.
~7.1~23.2
Liu et al. 10.5 ± 1.734.2 ± 5.5
Dupuy & Kraus 99 ± 16''

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

Space motion

WISE 1217+1626 has proper motion of about 1455 milliarcseconds per year.
WISE 1217+1626 proper motion estimates
Sourceμ,
mas/yr		P. A.,
°		μRA,
mas/yr		μDEC,
mas/yr		Ref.
Kirkpatrick et al. 1765148
Dupuy & Kraus ''''


The most accurate estimates are marked in bold.

Physical properties

Using three models, Liu et al. calculated physical properties of WISE 1217+1626 components.
From Burrows et al. models and M:
Component and
assumed age		Mass,
Teff,
K		log g,
cm/s2		P,
yr
A
B
A
B

From Lyon/COND models and M:
Component and
assumed age		Mass,
Teff,
K		log g,
cm/s2		P,
yr
A
B
A
B

From Lyon/COND models and Lbol:
Component and
assumed age		Mass,
Teff,
K		log g,
cm/s2		P,
yr
A
B
A
B