Infrared/Optical/X-ray Observations in 1980

W. Lewin and L. Cominsky, Massachusetts Institute of Technology, write: "We recently invited optical astronomers to participate in the 1980 simultaneous optical and x-ray observations of burst sources (IAUC 3420). We heard from A. W. Jones et al. of confirmation of the detection of infrared bursts from the Rapid Burster (IAUC 3344; Kulkarni et al. 1979, Nature 280, 819). The average luminosity at 2.2 um in the ~ 0.4-um bandwidth was ~ 10**30 J/s (assumed isotropic emission). These extremely bright infrared bursts are suspected to be associated with the Type I x-ray bursts from the Rapid Burster that repeat on a timescale of hours; Type II bursts repeat on a timescale of minutes or less (Nature 1978, 271, 630). If the infrared bursts are associated with Type I bursts, they are also expected from other Type I burst sources, and they would be much easier to detect than the optical bursts. Thus we also urge infrared astronomers to participate in the 1980 worldwide burst observations (IAUC 3420). To date, no infrared bursts have been detected from the Rapid Burster simultaneously with x-ray bursts, and the nature of the infrared bursts is still uncertain. The next opportunity to make simultaneous infrared/x-ray observations is expected to come some time in 1980 Feb.-Apr., when the Rapid Burster is due for its next turn-on."