TY - JOUR
T1 - Weather on the nearest brown dwarfs
T2 - Resolved simultaneous multi-wavelength variability monitoring of wise J104915.57-531906.1AB
AU - Biller, Beth A.
AU - Crossfield, Ian J M
AU - Mancini, Luigi
AU - Ciceri, Simona
AU - Southworth, John
AU - Kopytova, Taisiya G.
AU - Bonnefoy, Mickaël
AU - Deacon, Niall R.
AU - Schlieder, Joshua E.
AU - Buenzli, Esther
AU - Brandner, Wolfgang
AU - Allard, France
AU - Homeier, Derek
AU - Freytag, Bernd
AU - Bailer-Jones, Coryn A L
AU - Greiner, Jochen
AU - Henning, Thomas
AU - Goldman, Bertrand
PY - 2013/11/6
Y1 - 2013/11/6
N2 - We present two epochs of MPG/ESO 2.2 m GROND simultaneous six-band (r′i′z′ JHK) photometric monitoring of the closest known L/T transition brown dwarf binary WISE J104915.57-531906.1AB. We report here the first resolved variability monitoring of both the T0.5 and L7.5 components. We obtained 4 hr of focused observations on the night of 2013 April 22 (UT), as well as 4 hr of defocused (unresolved) observations on the night of 2013 April 16 (UT). We note a number of robust trends in our light curves. The r′ and i′ light curves appear to be anti-correlated with z′ and H for the T0.5 component and in the unresolved light curve. In the defocused dataset, J appears correlated with z′ and H and anti-correlated with r′ and i′, while in the focused dataset we measure no variability for J at the level of our photometric precision, likely due to evolving weather phenomena. In our focused T0.5 component light curve, the K band light curve displays a significant phase offset relative to both H and z′. We argue that the measured phase offsets are correlated with atmospheric pressure probed at each band, as estimated from one-dimensional atmospheric models. We also report low-amplitude variability in i′ and z′ intrinsic to the L7.5 component.
AB - We present two epochs of MPG/ESO 2.2 m GROND simultaneous six-band (r′i′z′ JHK) photometric monitoring of the closest known L/T transition brown dwarf binary WISE J104915.57-531906.1AB. We report here the first resolved variability monitoring of both the T0.5 and L7.5 components. We obtained 4 hr of focused observations on the night of 2013 April 22 (UT), as well as 4 hr of defocused (unresolved) observations on the night of 2013 April 16 (UT). We note a number of robust trends in our light curves. The r′ and i′ light curves appear to be anti-correlated with z′ and H for the T0.5 component and in the unresolved light curve. In the defocused dataset, J appears correlated with z′ and H and anti-correlated with r′ and i′, while in the focused dataset we measure no variability for J at the level of our photometric precision, likely due to evolving weather phenomena. In our focused T0.5 component light curve, the K band light curve displays a significant phase offset relative to both H and z′. We argue that the measured phase offsets are correlated with atmospheric pressure probed at each band, as estimated from one-dimensional atmospheric models. We also report low-amplitude variability in i′ and z′ intrinsic to the L7.5 component.
KW - brown dwarfs
KW - stars: low-mass
UR - http://www.scopus.com/inward/record.url?scp=84887564739&partnerID=8YFLogxK
U2 - 10.1088/2041-8205/778/1/L10
DO - 10.1088/2041-8205/778/1/L10
M3 - Article
AN - SCOPUS:84887564739
SN - 2041-8205
VL - 778
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 1
M1 - L10
ER -