Subject: Re: HIGH CADENCE IMAGING CAMPAIGN Date: Tue, 23 Apr 2002 12:34:50 +0200 (MET DST) From: Pavel Kotrc To: Richard Canfield CC: Petr HEINZEL Dear Dick, I would like to inform you about Ondrejov Astronomical Institute possibilities of high cadence optical observations, you can have a look at examples of our data and you can say if it is just good for cooperation for RHESSI team. First, a brief description of our facilities, telescopes and observing conditions. Observatory is located at 15 deg E and 50 deg N, it means at summer we can cover a time interval 4 UT till 16 UT, in winter from 7 to 14 UT. Generally, in summer time we have more sunny days than in winter. The mean number of solar optical observations during the last decade is a bit higher than 200 days per year. Seeing conditions are between 1 and 5 arcsec, depending on the weather and the season of the year. Seeing and weather are the most limiting factors of our observations. As concerns our optical telescopes: Solar patrol telescopes: 20cm/340cm and 21cm/280cm, one is used for white light observations of active regions (field of view of several arc minuts , the other for H-alpha (filter passband of 0.6 A) observations with practically comparable field of view. A small full disk image telescope is just to be finished at put into operation. We use analog video CCD cameras as detectors, i.e. 25 images per second. The data are registered on video tapes in a S-VHS standard, or transfered into DV (digital video). Then the analog data can be also digitized by a grabber in a dynamical range og 8 bits per pixel. They can be exported in FITS format. Examples of the data ca be seen at the www site: http://www.asu.cas.cz/~sunwatch/index.html Other technical information about the data can be obtained via e-mail address: sunwatch@asu.cas.cz Solar flare spectrographs: Currently, we operate 1 multichannel flare spectrograph 23cm/13500cm, equipped with 4 videocameras with the same kind of detectors, similar conditions and time schedule of observations as it is decribed at the solar patrol above. We observe spectra of active phenomena, mostly flares and eruptive prominences in H-alpha, H-beta (or He D3) and CaII 8542 A, plus slit-jaw image through H-alpha filter of a passband 0.6 A. In addition to that, sometimes we use one branch of the spectrograph for taking solar polarization in H-alpha using a simple device (Wollaston prism + rotating lambda/4 plate and we recieve two strips of linearly polarized light. All the images are registered simultaneously and the analog video CCD detectors are mostly the same as it was decribed before. The field of view of the slit jaw is a comparable to thet at solar patrol observation, i.e. usually enough to cover one active region. Time (UT) is registered directly into the video data, as can be seen on the examples at the site: http://www.asu.cas.cz/~pkotrc/index.html We are preparing to move our multicamera flare observations in a larger modernized telescope during this year, where the local seeing should be better. Then we have also radio observations with a high time resolution, see the homepage. As concerns to the time schedule for observations, we have the telescopes to our disposal and it is only a question of weather and our decision to what kind of observations we will use them. As we are on the e-mail, we can change the targets immediatelly after receiving the RHESSI team demand. I am sorry, that I replied so late to your e-mail, and not exactly in the right order of the questions. But I think I gave you the basic information and I am ready to answer any questions. Best regards Pavel Kotrc ******************************************************************** * Astronomicky' u'stav Astronomical Institute * * Akademie ve~d C~eske' republiky Academy of Sciences of CR * * Ondr~ejov Ondrejov * * PSC~ 251 65 CZ-251 65 * * C~eska' republika The Czech Republic * * --------------------------------------------------------------- * * tel. ++ 0204 620 222 / ++ 0204 649 383, FAX ++ 0204 620 110 * * mobil tel. +420737774512 * * E-mail: pkotrc@asu.cas.cz * * http://www.asu.cas.cz/~pkotrc/index.html * ******************************************************************** On Wed, 10 Apr 2002, Richard Canfield wrote: > The RHESSI team seeks collaborators at ground-based and space-based > observatories to participate in a High Cadence Imaging Campaign. RHESSI > is capable of making high-quality hard and soft X-ray movies with a > cadence of 2 seconds (half spin) and even down to 10s of ms for intense > events, and seeks collaborators at observatories working in other > spectral bands (H-alpha, radio, EUV, continuum, ...) who can make > observations at similar cadence. > > Please contact me by telephone or e-mail to discuss imaging observations > you can achieve with a temporal cadence of at least 2-4 seconds: > > 1. What field of view can you observe at this cadence? (RHESSI sees the > full Sun, but we presume that observations will be aimed at a specific > active region chosen by the Max Millennium Chief Observer) > > 2. What spectral bandpass(es) can you observe? (RHESSI's bandpass is > limited by both detector response and source strength but usually covers > from 3 keV to 17 MeV. Thus, it is interesting to make observations over > a broad range of flare sizes from small soft X-ray B and C flares to M > and X gamma-ray flares). > > 3. In what UT time range and seasons can you observe? (RHESSI > observations are continuous, interrupted only by night in Low-Earth > Orbit and SAA). > > 4. Can you participate in a Target-of-Opportunity campaign at very short > notice, or must we pick a fixed schedule? (RHESSI would welcome > collaborators in either campaign mode, since both have unique advantaqes > and disadvantages). > > 5. If we must pick a fixed schedule, how far in advance must fixed dates > be chosen (RHESSI requires no advanced notice since it is expected to be > continuously operating in the same near-autonomous mode.) > > Of course, we are interested in non-imaging data at high cadence and > lower-cadence imaging data as well, but in response to this message I > would most urgently like to hear about the high-cadence imaging > discussed above. > > I look forward to hearing from you. > > Dick > > Department of Physics E-mail: canfield@physics.montana.edu > Montana State University Telephone: (406) 994-5581 > P.O. Box 173840 Fax: (406) 994-4452 > Bozeman, MT 59717-3840 USA http://solar.physics.montana.edu/canfield > ====================================================================== > FedEx etc: Physics Dept, EPS 264, Montana State Univ, Bozeman MT 59717 > ====================================================================== >