Subject: RE: HIGH CADENCE IMAGING CAMPAIGN Date: Fri, 12 Apr 2002 11:56:32 +0200 From: Jean-François Hochedez To: "Richard Canfield" , CC: Frédéric Clette ,"Stein Vidar Hagfors Haugan" ,"Kevin Schenk" ,"Verwichte E." , "Berghmans D." ,"Gurman J." ,"Einfalt E." ,"Cds Planner" ,"alex.young" ,"Dawn Myers" ,"Fludra A." ,"Harrison R." ,"Jake Wolfson" ,"Trace Planner" ,"soc" , "Koutchmy S." ,"Frédéric Auchère" ,, ,,"Terry Kucera" ,"Russell Howard" ,"Barbara Thompson" ,"Jack Ireland" ,"Jonathan Cirtain" Dear Richard, The EIT-SOHO team has undertaken in late 2000 a synoptic program of "high-cadence" observations. It is meant to be run 4 times a year or more, depending essentially on DSN availability. Other intruments/teams have regularly joined (TRACE, CDS-SOHO), and the program is now routinely scheduled. You can find further information at http://sol.oma.be/High-cadence/. The basics for EIT are: 1' cadence (appropriate to EIT spatial resolution), 2 hours duration, quarter disc FOV. EIT alternates its 304A and 195A bandpasses, while TRACE has mostly selected its 171A BP. Early results of this programme will be presented in September 2002 in Prague (http://wave.asu.cas.cz/spm10/abstracts/section5/abstracts_dbs_59.pdf). Although larger flares are feared for our instruments health, coordination with the RHESSI team would be of the highest value. Best Regards, Jean-François Hochedez mailto:j-f.hochedez@oma.be Tel: +32 2373 0302 Fax: +32 2374 9822 Royal Observatory of Belgium Solar Physics Department Circular Avenue, 3. B1180 Brussels Belgium http://sol.oma.be http://bold.oma.be/ http://homepage.oma.be/hochedez/ > -----Original Message----- > From: owner-mmscience@mithra.physics.montana.edu > [mailto:owner-mmscience@mithra.physics.montana.edu]On Behalf Of Richard > Canfield > Sent: jeudi 11 avril 2002 06:57 > To: mmscience@mithra.physics.montana.edu > Subject: HIGH CADENCE IMAGING CAMPAIGN > > > 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 > ====================================================================== > Subject: RHESSI TOO high-cadence campaigns (EIT not) Date: Fri, 12 Apr 2002 09:53:16 -0400 From: "Joseph B. Gurman" To: canfield@mithra.physics.montana.edu CC: hochedez@oma.be, soc@soc.nascom.nasa.gov, Kevin Schenk Hi, Dick - > > 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: I saw Jean-Francois Hochedez's response to your request for a high-cadence imaging campaign, and thought it might help if I made it clear that EIT simply cannot observe at 2 - 4 s cadence. The 1 minute shutterless cadence Jean-Francois describes is about a factor of ~ 2 longer than the best we have ever done in shutterless mode, but even that represents a significant decrease in the field of view. (Also, given the damage we could do to the detector during a sizeable event anywhere on the Sun during shutterless ops, we have to schedule the runs for a "good" DSN station, which means a minimum of 3 - 6 months in advance, so we can bail in mid-observation if there's too much EUV flux.) Using the shutter (our normal exposure mode), we can image small areas of the Sun (~ 8 x 8 arc min) every 60 s, but the shutter motor starts overheating in 45 m or so. Our exposure times alone for the lines to which we are more sensitive (171 and 195 Å) are 2 -3 the cadence you are seeking. For the lines for which we have poorer response (284 Å and 304 Å), the exposure times are 30 - 60 s. I'll let people more knowledgeable than I answer for TRACE, but the 2 - 4 s cadence is out of the range of EIT. Best, Joe -- "I love deadlines. I love the whooshing sound they make as they go by." - Douglas Adams, 1952 - 2001 Joseph B. Gurman, NASA Goddard Space Flight Center, Solar Physics Branch, Greenbelt MD 20771 USA