Astrosat is a multi-instrument orbiting observatory that was launched in 2015 by the Indian Space Research Organization (ISRO). The same field of view is observed simultaneously at wavelengths ranging from gamma ray to the optical blue. This talk described the observatory’s performance, with emphasis on time-domain studies, and gave examples of results.

We have presented the observations of O VI absorption at 1032 Å towards 22 sightlines in 10 superbubbles (SBs) of the Large Magellanic Cloud (LMC) using the data obtained from the Far Ultraviolet Spectroscopic Explorer (FUSE). The estimated abundance of O VI in the SBs varies from a minimum of (1.09 ±0.22)×1014 atoms/cm2 in SB N206 to a maximum of (3.71±0.23)×1014 atoms/cm2 in SB N70. We find about a 46% excess in the abundance of O VI in the SBs compared to the non-SB lines of sight. Even inside a SB, O VI column density (N(O VI)) varies by about a factor of 2 to 2.5. These data are useful in understanding the nature of the hot gas in SBs.

We present GALEX ultraviolet (UV) emission results of star-formation in a small sample of nearby, gas-rich early-type galaxies. The first observational evidence of star-formation in this sample was presented by Leeuw et al.2008, using 350 μm continuum data. The measured far-infrared (far-IR) excess of these galaxies showed that the most likely and dominant heating source of the observed 350 μm continuum emission from dust is star-formation, that could have been triggered by an accretion or merger event. Consistent with starbursts that are less than 1 Gyr (e.g., Kaviraj 2010), the GALEX near-UV (NUV) minus SDSS r-band emission of the galaxies is < 5.5. The UV results corroborate those of mid-IR to radio data for the sample.

We present early time (~0-50 days) bolometric light curves of UV-bright Core Collapse Supernovae observed with the Swift UV/Optical Telescope. We also generate pseudo-bolometric light curves from Swift UV and optical data and examine these by subtype as well as the observed and interpolated UV and IR flux contributions by epoch and bolometric corrections at early times from UV data.