Wednesday, August 11, 2021
Recurrent Nova RS Ophiuchi in outburst
|Western sky as seen from Adelaide at 23:00 ACST the position of RS Oph is marked with a circle.Click to embiggen.||Approximate binocular view of the area around RS Oph the position of RS Oph is marked with a circle.. Click to embiggen.|
The recurrent nova RS Ophiuchi is in outburst for the first time in 15 years. This is its first outburst since February 2006, brightening from magnitude 12 to an unaided eye visible (but still relatively dim) magnitude 5. Located between the bright stars Antares and Altair, near mu (μ), nu (ν) and tau (τ) Ophiuchi (see charts above) it will be readily visible in binoculars and just visible to the unaided eye.
Over the coming week it will fade back below unaided eye visibility, and it will be interesting to watch the progress of its dimming.
Chart of the stars around RS Oph (black rectangle) showing magnitude labels  mean magnitude 6.84 etc. click to embiggen and print. Use the charts above to orient yourself.