Observations of ultracool dwarfs with ULTRACAM on the VLT: a search for weather
Abbreviated Journal Title
Mon. Not. Roy. Astron. Soc.
stars : individual : Kelu-1; stars : individual : 2MASS 1300+1912; stars; : individual : 2MASS 2057-0252; stars : individual : DENIS 1441-0945; stars : low-mass; brown dwarfs; BROWN DWARFS; PHOTOMETRIC VARIABILITY; ATMOSPHERES; KELU-1; STARS; DUST; MULTIPLICITY; Astronomy & Astrophysics
We present multicolour photometry of four-field ultracool dwarfs with the triple-beam photometer ULTRACAM. Data were obtained simultaneously in the Sloan-g' band and a specially designed narrow-band Na I filter. The previously reported 1.8-h period of Kelu-1 is here recovered in the g' band, but the lack of any significant variability in the Na I light of this object precludes any conclusion as to the cause of the variability. 2MASS 2057-0252 and DENIS 1441-0945 show no convincing evidence for variability. 2MASS 1300+1912, on the other hand, shows good evidence for gradual trends in both bands at the 5 per cent level. These trends are anticorrelated at a high level of significance, a result, which is incompatible with models of star-spot induced variability. It would seem likely that dust-cloud 'weather' is responsible for the short-term variability in this object.
Monthly Notices of the Royal Astronomical Society
"Observations of ultracool dwarfs with ULTRACAM on the VLT: a search for weather" (2006). Faculty Bibliography 2000s. 6365.