Subject: Re: HIGH CADENCE IMAGING CAMPAIGN Date: Mon, 15 Apr 2002 12:25:26 +0200 (CEST) From: Gianna Cauzzi Organization: Osservatorio Astronomico di Arcetri To: canfield@mithra.physics.montana.edu CC: Cauzzi Gianna hello Dick, I thought of answering your request about high cadence data. We (in Florence) are completing a double Fabry-Perot instrument that should be of interest also for activity studies at high resolution. Indeed, we would like to use it in coordination with RHESSI. According to plan, the instrument will be assembled at the Tower in Sac Peak at the end of June, and should provide scientific data by the beginning of August after a period of tests/calibrations. Data as follows: 1- images over a 80x80 arcsec FOV 2- any desired wavelength within selected lines (much as the IVM but no polarization for now). We will have pre-filters for the following lines: FeII 7224 (deep photosphere, g=0) FeI 7090 (photospheric, g=0) FeI 6301+6302 NaI D2 CaII 8542 The last two are of course most interesting for activity. In particular we planned to use the CaII line to measure chromospheric flows during activity. We decided on this line vs H-alpha because the latter is too large for the free spectral range of the instrument (few Ang). 3- Cadence is about 3 images/sec, so temporal resolution varies with number of wavelengths sampled. Faster if one reduces the FOV. In few seconds (4-5) one can fully sample a line, and get all the spectral info needed for re-constructing the profile and measure velocities. This is the mode we were planning to use for activity studies. 4- Spatial scale fixed at about 0.15"/pix. We hope to take advantage of the AO system at Sac Peak. 5- All of the above makes the instrument more suitable for smaller flares rather than big ones. 6- An H-alpha filter can (and will) be run in parallel, with cadence of less than 1 sec if observing at a single wavelength, or 2-3 sec if cycling through few wavelengths. Depending on the SP policy for the future (you saw that they want to simplify the observations somewhat), we would like to run also a spectrograph, fixed slit position, to get the CaII K at a cadence of few sec. 7- Being at Sac Peak, we can observe between 14:30-24:00 UT (in summer) or 15:30-23:00 UT in fall-winter. The first part of the day is the best. 8- Fixed schedule must be used. Sac Peak requires proposals by May 15 for the Jul-Sept quarter; Aug 15 for Oct-Dec; etc. 9- We are planning on asking time for the beginning of August, and again in October. Say 8-10 days each period, dedicated to (small) activity studies, high resolution. If all goes well, the instrument will be a facility of SP starting from the October quarter, so other people might use it as well. Since we are not there yet, all of this might look just blah blah, but we are cautiously optimistic that this schedule will be followed and everything will work as planned. cheers, Gianna