This just in from the folks at Sky & Telescope:

For first time in 21 years, and the sixth time in recorded astronomical history, the recurrent nova RS Ophiuchi has erupted into naked-eye visibility. As late as February 10, 2006, the star was still magnitude 11.0, where it spends most of its time with only minor fluctuations. But on the morning of February 13th it was reported shining at magnitude 4.8.

We should know tonight whether the star has hit its peak or is still on the way up!

Both amateur and professional astronomers have been anticipating this event for years. See our article “When Will RS Ophiuchi Next Blow Its Stack?”

Sweet!

Click on the thumbnail for a chart.

RS Ophiuchi has similarly erupted in 1898, 1933, 1958, 1967, and 1985.

I sure hope pre-dawn conditions cooperate here so I can go out and take a peek despite the fact that the Moon will be blazing away, nearly full. RS Ophiuchi will still make for a fine target even using binoculars, so if you have the chance to get out and peek, seize the opportunity!

Added 15 February

Here’s the latest update I’ve seen:

In the last two days RS Oph has been fading and reddening, losing about 0.4 magnitude per day according to visual reports sent to the AAVSO. As of Wednesday morning (February 15.3 UT), RS Oph was about magnitude 5.7. The star’s low altitude and the full moonlight may or may not be affecting visual estimates and other measurements. Check back here for further developments.

Bummer, I was hoping it’d really erupt. It was overcast here this morning; hopefully conditions will allow for observing pre-dawn.