we propose to use isocam to look for brown dwarfs which are members of the hyades cluster. previous studies of the hyades and similar young clusters have produced only ambiguous results to date. the problem is two-fold. for the youngest clusters (taurus and ophiuchus), the brown dwarfs are so young that their temperatures are high enough, >2500k, that it is easy to confuse them with field stars, especially if there may be some reddening from dust extinction. the previous studies in the hyades have been performed in the optical and near infrared (2.2 microns). these studies have located some candidate brown dwarf members. however, even if ultimately it can be proven that these objects are true hyades members, they have characteristics (luminosity and temperature) of objects just at the borderline between low mass stars and bona-fide brown dwarfs. by employing the longer wavelength (7 microns) of isocam, we will be sensitive to any brown dwarfs in the 0.015 to 0.060 solar-mass range, which is inaccessible to the ground-based searches. furthermore, the temperatures of these objects will be so low, below 1500 k, that their identification as brown dwarfs will be unambiguous. we estimate that a search of about 25 hours will detect brown dwarfs, even if they are no more numerous than the known stellar hyads and therefore comprise a small fraction of the mass of the hyades. thus we will begin to explore the mass function of this cluster below 0.06 solar masses for the first time.
Instrument
CAM01 , PHT32
Temporal Coverage
1996-03-30T05:41:44Z/1998-03-19T20:25:38Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the world's first true orbiting infrared observatory. Equipped with four highly-sophisticated and versatile scientific instruments, it was launched by Ariane in November 1995 and provided astronomers world-wide with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the Universe at infrared wavelengths.
