Perhaps I could chat a bit about what are the various streams that Skyalert is slurping and spitting.
The front page, http.skyalert.org, shows a timeline of recent events — it is the dark blue panel with colored dots on it that comes up a few seconds after the main page. If it does not come up, and you continue to see “waiting for event server”, then you should make sure that Javascript is enabled in your browser. The most recent events are to the right, and the scale at the bottom of the chart shows the ages of the events, in a quasi-log plot from an hour to a day to a week to a month.
A prolific provider of events is the Catalina Realtime Transient Survey, which has three event streams called prosaically CRTS, CRTS2, and CRTS3 for the three telescopes, which are (respectively) on Mt Bigelow in the Catalina mountains near Tucson, Arizona, on Mt Lemmon, also in the Catalina Mountains, and at Siding Spring in Australia. These three telescopes operate much of the month, except near full moon, each delivering perhaps a dozen or more transients on a bountiful night. A related stream is the Catalina Sky Survey, called CSS_NEO for short, which operated from the same telescopes and data stream as the CRTS survey. The difference is that CSS_NEO reports the moving objects from the data stream, and CRTS reports stationary objects whose magnitude has increased. The discovery of moving objects (that might be “killer asteroids”) is the primary funding motivation for the survey, and also explains the timing: each event that Skyalert displays has four images, 20 minutes apart, and a fifth, deeper image that combines previous observations. The cadence of 20 minutes is carefully chosen to make clear the drift of an asteroid. CSS_NEO events come with both the observation record (where the asteroid was seen), and also a predicted ephemeris for the next few hours so that rapid followup is possible.
Another prolific stream is MOA: Microlensing Observations in Astrophysics, which runs a 1.8m telescope in the Southern Alps of New Zealand, with Japanese collaborators. It makes observations on dark matter, extra-solar planets and stellar atmospheres using the gravitational microlensing technique.
NASA also contributes several event streams. The SWIFT satellite has been catching Gamma-Ray bursts since 2004, and has now reported its 500th burst. Its discoveries range from a nearby nascent supernova to a blast so far away that it happened when our universe was only 5 percent of its present age. NASA also supplies events from the Fermi observatory, also in orbit, which reports events from the burst monitor instrument (GBM) in the photon energy range 8 keV and 40 MeV. We hope that in the future the other main instrument of Fermi (Large Area Telescope) will also be reported publicly so that Skyalert can report them.
Soon, Skyalert will be reporting another prolific stream, from GALEX, another NASA satellite, in orbit since 2003, surveying the ultraviolet sky. The transients are currently reported at the GALEX transients page, and we are working to convert these to Skyalert format.
The theme of Skyalert is near-real-time reporting of astronomical events, and we have agreements from many such providers that have not yet begun to produce events on a regular basis. And there are, of course, several privately-held astronomical event streams that do not want their events distributed to the public.
This is a great resource, useful for anybody interested in this topic.