By Denis Mourard
December 19, 2020 (UT) marked the last night on sky with the VEGA instrument at the CHARA Array. Olli, Fred, and Denis participated in the last night of observations, but the seeing was not great.
The VEGA history started in May 2005 with the first email exchanges between Hal McAlister, Steve Ridgway, Theo ten Brummelaar, Vincent Coude du Foresto, and Denis Mourard, followed by Denis' first visit to the Mountain (with Jean-Michel and Stéphane and a measuring tape) in November 2005. Very soon after that, we obtained strong support from the CHARA team (letter from Hal and green light after the 2006 Tucson Year Two Science Meeting together with Philippe). The adventure started with the adaptation of the GI2T/REGAIN spectrograph for its installation in the CHARA lab.
In August 2007, 8 boxes weighing about 1200 kg were sent to Mt Wilson, and after three weeks of integration we obtained the first fringes on 30 Sep 2007. Thanks to Aurélie, Jean-Michel, Yves, Chris and Antoine and the whole CHARA staff. Hal was there also but did not show up because he worried that his being on the mountain would bring bad luck!
The next steps were 3T fringes on 9 Oct 2008, first remote operation in summer 2009, simultaneous CLIMB and VEGA operation in May 2010 and finally the first 4T fringes on 12 Oct 2010 together with MIRC. Upgraded detectors and group delay tracking were implemented in 2012.
19 Dec 2020, was the 509th night of VEGA with data. Almost 770 different stars have been observed and 8500 individual observations were recorded. 47 papers have been published and a few more are in preparation. With spatial resolution down to 0.2 mas and spectral resolution up to 30000, VEGA has addressed some unique science cases in measuring the fundamental parameters of stars and in the study of stellar environments.
CHARA/VEGA was not only a fantastic scientific adventure but a wonderful human story also. So many people have to be thanked for all of this 15-year period shared together. Hal, Theo, Doug, Judit, Laszlo, Nils, Gail, Chris, Larry, Steve, Matt, Norm, Olli (and PJ, Bob, Dave and probably more, Sandy, Alicia...) thank you so much for your continuous support and the fabulous spirit of the CHARA collaboration.
But this is not the end of the story! Pieces of VEGA (thanks Judit) will reincarnate in the next generation visible combiner SPICA very soon. We are ready to start the SPICA integration in Nice and I'm looking forward for its first light within one year from now!
Bye bye VEGA, Happy New Year to SPICA and Merry Christmas to all of you.