Subject: High cadence observations Date: Wed, 15 May 2002 15:18:20 +0200 From: Gilbert Chambe To: canfield@physics.montana.edu Dear Dr. Canfield, Sorry for the previous empty message. I made an error in the mail handling. I am presently collaborating with Jean-Marie Malherbe in the task of performing high cadence flare observations in Meudon and in other french observatories. I am sorry for beeing so busy i could not respond sooner to your appeal, but it will be of no consequences since we presently observe whenever possible in Meudon and shall have observing campaigns at other sites only later in this year. In Meudon we can perform high cadence imaging in Halpha, using a 20 cm refractor - the same telescope that makes the full disk routine observations at 1 mn cadence - a Lyot filter and either an analogical or a digital video camera, both operating at 25 images per sec. The choice depends on our available time for observing, since the shorter duration of the digital tapes (1 hour) requires a more permanent surveillance. The dg. camera has about 750x580 pix., but the signal is coded on 8 bits only. 1. Field of view : about 7'x5' 2. Bandpass : 0.5 A at Halpha center 3. Observing time range : 07 to 15 UT, but often less or none due to poor weather conditions. Season : march through to october, could be. Last year : Only june and part of july . 4. We can participate in target-of-opportunity campaigns at short notice, including the may 20 june 2 campaign. However, since we lack in permanent observers, I cannot guarantee a hundred percent time coverage even during acceptable seeing conditions. We'll have also a THEMIS campaign, at the Izana observatory, november 7 - 12. We shall perform simultaneous imaging observations, with the same digital camera put behind a Lyot filter, and spectro-imaging observations, using the spectrograph in the MSDP mode (Multi-chanel Substractive Double Pass). A --- Imaging : 1. FOV : 4'x3' 2. Bandpass : 0.25 A at Halpha center. B --- Spectro-imaging : The MSDP will provide 9 simultaneous images at 9 positions in the spectral profile of the selected line. The following characteristics are for Halpha (they may slighty differ for other lines) : 1. FOV : 120''x25'' 2. Bandpass : 0.240 A per chanel, i.e. a total useful band of 2 A. * Time cadence : 1 s if we operate at a fixed spatial position. A little slower if we scan. So for instance count about 20 s for a total field of 120"x120" achieved with ten 12"-steps. C --- 3. Observing time range could be 8 to 18 UT if weather allows. Frequently conditions degrade after the first few hours. 4. The dates are fixed . In addition, we are now installing the same kind of instrumentation at the Pic du Midi observatory. I shall tell you more when we are ready. So our means are modest, but I think you may add Meudon to your list of contributing observatories. If you need more information, please ask me. Best Regards, Gilbert Chambe - Observatoire de Meudon, LESIA, 92195 Meudon, France E-mail : gilbert.chambe@obspm.fr Tel : 01 45 07 77 93