Okay Hubble, You're Safe To Go

The AAVSO has your back.

It's not always obvious why I find observing cataclysmic variables particularly fun and exciting. I admit some nights it seems like a lot of effort for little return. Other nights a whole slew of stars I monitor will all be in outburst at the same time, like so many thermonuclear explosions ignited in space for my viewing pleasure. Occasionally, we get asked to monitor specific stars as part of an AAVSO campaign, in collaboration with professional astronomers in need of specific data.

That was the case early this week. Paula Szkody, an astronomer from the University of Washington, and her team had been approved for time on the Hubble Space Telescope. They planned to observe the cataclysmic variable GW Librae on Wednesday in ultraviolet wavelengths with the Cosmic Origins Spectrograph (COS). What they needed from us was pretty simple, but very important. They wanted to be absolutely sure the star was in its faint state, quiescence. The COS is the most sensitive ultraviolet spectrograph ever flown on Hubble. They can't look at anything as bright as 14th magnitude with it without risking damage to the detector. If GW Lib suddenly erupted while HST was pointed at it very bad things could happen, and there are no more scheduled servicing missions.

A handful of observers, including me, were able to observe the system in advance of the HST run, and we reported it was safely inactive at the time. This enabled the mission team to give the go ahead for the HST observations. Me, personally, I dragged myself out of bed at 3AM to get my early morning observation of GW Lib, a star I don't normally monitor because it is so far south, at -25 degrees declination. But, I am well aware of the fact that there aren't that many observers out there willing to do this kind of stuff, and on any given night I might be the only one anywhere looking at the star I am observing. I didn't expect any big reward; just the satisfaction of knowing I did my little part to enable science to push the boundary of our knowledge another inch forward.

Today, I got an email from Paula Szkody, addressed to all seven of the observers who contributed data, thanking us for enabling the team to get the HST COS observation they wanted. She wrote:

"Hi -
I just wanted to thank all you great observers for the data you took in the last few days on GW Lib (esp last night when it was critical to get a magnitude to HST this morning). Your observations enabled HST to give the go-ahead for the COS UV observation to proceed tonight. THANK YOU! "

You mean they wouldn't have pointed that big ole satellite at GW Lib without us telling them it was okay?

That's right. Pretty cool, eh?