JOP057 "Joint SOHO/YOHKOH/Ground-Based Observations of Polar Jetlets" An update of JOP 57 to be run during the 3rd week of the May99 MEDOC campaign ( contacts JP DELABOUDINIERE >> boudine@ias.fr ) A Scientific rationale : -------------------- 1) Accurate observations of the solar limb with EIT and ground based observatories have shown that the solar limb departs from a perfect circle in selected emissions radiated by the chromosphere and the lower corona . 2) Macrospicules activity is blurring and apparently pushing the limb upward by several arcsec in the regions of coronal holes . This effect is stronger in the 304 A line of HeII . 3) Clearly the definition of the limb is uncertain due to the transient nature of spicules and macrospicules . Much more dedicated observations are required to progress. B Suggested Observational program ------------------------------- We want to obtain detailed observations of the contours of spicules and macrospicules at different wavelengths using a high temporal cadence in order to make direct comparison of observations easy and significant. Of particular interest are chromospheric emissions from H , He , Ca in the following lines : H H alpha and Ly alpha 6563 A and 1216 A He+ Ly alpha 304 A Ca+ CaK 3934 A The instruments involved will be : EIT HeII 304 A and 195 A or 171 A for solar context TRACE H 1216 A and 195 A or 171 A and 1700 A for solar context HACO II (Pic du Midi) H alpha (line center) and continuum for solar context SVST (Las Palmas) H alpha (2 points +700 ma and +0 ma) ,Cak , and G band , Iron I for solar context. The cadences are the following : EIT every 20 sec context at the beginning and end of sequence TRACE every 20 sec context every few minutes HACO every 20 sec interleaved context SVST every 20 sec interleaved context The fields of view are : EIT 192x96 pixels pixel size 2.6 arcsec TRACE 512x512 pixels pixel size 0.5 arcsec HACO II 1024x1024 pixels pixel size 2.5 arcsec SVST 512x512 pixels pixel size 0.2 arcsec The duration is limited to ONE hour by EIT in shutterless mode Several runs separated by 2 to 3 hours (to let EIT cool off) can be programmed each day during daylight in Europe ( 06 UT to 18 UT ) The target North/South pole or East/West equator will be defined the day before Relative heights can be precisely deduced by coalignement using the same line in different instruments or comparable (i.e. continuum) context observations when necessary ------------------------------------------------------------------------- =============================================================================== From hara@solar.mtk.nao.ac.jp Sun Jun 22 11:44:20 1997 To: bfleck@esa.nascom.nasa.gov, calendar@esa.nascom.nasa.gov, cdp@ast.star.rl.ac.uk, gurman@gsfc.nasa.gov, hara@flare2.solar.isas.ac.jp, harrison@solg2.bnsc.rl.ac.uk, koutchmy@iap.fr, suematsu@spot.mtk.nao.ac.jp, sxt_co@isass0.solar.isas.ac.jp, watanabe@spot.mtk.nao.ac.jp Subject: JOP057 Proposal of New JOP057 Hirohisa Hara(NAO) 1. Objective of New JOP057 We found jet-like events in polar coronal holes with the soft X-ray telescope aboard YOHKOH two years ago (Aug 1995; see figure 1 of Koutchmy and Hara et al. 1997) during the search for X-ray counter-part of the so-called `polar spikes' which are seen in H-alpha. JOP057 was organized to understand relationships between the X-ray polar jets and polar spikes. EIT/SOHO, CDS/SOHO, MDI/SOHO, SacPeak observatory, and SXT/YOHKOH observed a northern polar coronal hole in Dec 1996. Although SXT observed a lot of polar jets, JOP057 did not run at the same time. This is because the observing windows of YOHKOH were a little bit different from those of the SOHO JOP057 observing windows. I saw the CDS data obtained during this campaign observation. A polar jet seemed to be observed with CDS. A raster image of Mg X included a jet-like feature, and the structure disappeared in the next raster image obtained 40 min later. Therefore, this is not a polar plume, which is seen in Mg IX as a stable bar structure in the raster images during the same observing time. I felt that the cadence of observation should be faster. I prepared an observing table of CDS with Dave Pike to make it faster when I visited RAL last March. 2. Plan of Observation Target area: a northern polar coronal hole. Time of Observation: 20 - 22 UT from 30 June to 3 July. CDS: The target observing area should include the limb of the Sun. The observing table has been already prepared by myself and Dave Pike. The test run was done on 17 April 1997. The fits file name is s7635r00.fits, and the observing table was PCHJET_R. The location of the solar limb in the image is at the central part of the observing area in the north-south direction, shown in s7635r00.fits data. The center of the field of view was set at (0",966") in the test run. We satisfied the location of the test run. The following is the sequence of observations that we request. Date Time Table Name Note Reference Data 30 June 1997 20-22 UT: PCHJET_R raster by 4" slit 40 steps s7635r 1 July 1997 20-22 UT: PCHJET_R raster by 4" slit 40 steps s7635r 2 July 1997 20-22 UT: PCHJET_R raster by 4" slit 40 steps s7635r 3 July 1997 20-22 UT: PCHJET_M raster by 90" slit 3 steps s7636r <> Cadence of PCHJET_M is much fast. Before running this table, please discuss if we can use this observing table with Richard and Dave. If they do not allow to use it, please use PCHJET_R table for 3 July observation. EIT: If EIT can participate in this JOP, we request the observation in Fe XII line. The 300"x300" area in a northern coronal-hole region is requested to be observed. At the middle row of the observing region, the northern limb of the Sun is set. A high cadence better than 2 min is requested. SXT: The observing table used in Dec 1996 run should be modified slightly. We will include the exposure with thin-Al filter to estimate the temperature of polar jets. The size of observing area is not changed. The cadence of a pair of exposures, AlMg and Al.1, becomes 1 min. The observing table will be modified by myself. The contact passes that we change the SXT observing table for this JOP will be informed to the SXT chief observers later. 3. Reference SXR Coronal Flashes: Koutchmy S., Hara H., Suematsu Y., and Reardon K. 1997, Astron. Astrophys., 320, L33-L36. end of document ===================================================================================== ==================================================================================== JOP057 "Joint SOHO/YOHKOH/Ground-Based Observations of Polar Jetlets" by: IAP-CNRS: S. Koutchmy ; C. Delannee; G. Stellmacher; IAS-Univ. Paris XI: JP. Delaboudiniere; J-C Vial; K. Bocchialini; NSO/T. & IAS: F. Baudin; NAOJ: K. Shibata; H. Hara; Y. Suematsu; NRL: K. Dere; PdM: J-C Noens; Athens: A. Georgakilas; H. Dara; Version: 01-NOV-96 e/mail address: koutchmy@iap.fr mail/Institution: Institut d'Astrophysique de Paris- CNRS 98 bis Bd Arago F-75014 Paris (France) phone: 33 1 4432 8056 fax: 33 1 4432 8001 Type of request: once per semester run A- Scientific Presentation : ----------------------- The polar surge activity (S-prominence) has been known for a long time. Because the background magnetic field in polar regions at sunspot minimum is presumably rather simple, numerical models developped to simulate a surge-like event could be applied with success to events occuring there. Brightenings in different lines formed at chromospheric altitudes are well observed during the impulsive phase; they strongly suggest that highly non- linear magnetic dissipation phenomena are at work in the underlying region. Finally, the spicule- like activity of polar regions seems easier to analyse because the network looks simpler than at moderate latitudes and ejections are more vertical, strongly supporting the assumption that they are at least partly responsible for the fast wind. We want to clarify the relationship between (quasi- stationnary) polar jet like features seen in EUV (EIT), in W-L (Eclipses), and the SXR jets & jetlets recently analysed using SXT sequences from Yohkoh. Their possible associations with (small) disk- brightenings and/or magnetic concentrations are interesting to look at, along with the evidence of waves (e.g. with the use of K CaII high temporal resolution filtergrams). Additionally we want to determine the possible relationship between off-the-disk SXR (Yohkoh) small-transient-compact-brightenings or flashes (similar to those seen on the disk), and outwardly moving small plasmoids seen in HeII 30.4 nm and/or in Halpha, over polar regions (giant- spicule like), with the aim to post-facto identify the site of magnetic dissipation and/or explosion. Finally, we want to use this opportunity to also look at the prominence- corona interface (PCI) where potential sites of magnetic explosive dissipation exist during the activation phase. B- Proposed Operations : ------------------- - Get several short (20 to 40 mn during slots of 2 hours) runs of SIMULTANEOUS observations from i/ SXT of Yohkoh ii/ EIT, SUMER/CDS of Soho and weather permitting iii/ ground-based telescope(s); - For EIT, use a 'partial frames' of 64x256 px mode of observation and full resolution with 1px= 2.5 arcsec on images; - Collect data over a polar region, centered on the pole but slightly shifted to have more disk (3/5); eventually, look nearby; - Use long enough exp. time and the highest possible cadence which should be of order of 60 s (EIT), 40 s (SXT) and 15 s (G-B); - Filters on SXT/Yohkoh: Al/Mg/Mn and 30 sec exp.time; on EIT/Soho: FeXII 19.5 nm channel & especially HeII 30.4 nm; - Get SUMER sequences at the same time with a 1" width slit crossing the Pole in the spectral region of lines of chromospheric and coronal origin; because of the present state of SUMER pointing, the proposed program is a minimal one in terms on mechanisms constraints: fixed position at the North (or South) Pole; S VI (944.5 and 933.4), Lyepsilon (937.8), Lyman 6 (930.7) full profiles; exposure time: 25s; no X move. - The positioning of the SUMER slit would benefit from CDS observations (images) in HeI 584 A to be overlapped with Lyman SUMER observations. - Because the new activity- cycle started in both hemispheres, the pole to be observed is not defined well in advance; it will be decided 3 weeks before the run, after analysing the preceding rotation; C- Ground-based observations: ------------------------- - Simultaneous UBF observations will be made at the NSO/Sacramento Peak VTT at different positions of the H-alpha line, HeID3, continuum and b1-40 pm line; - Simultaneous CaII K2 filtergrams will be collected at the NSO/SPO ESF at high cadence; - Complementary observations will be made with the Pic du Midi Halpha coronagraph (JC Noens) at high cadence (off-disk). D- Spaceborne Observations: ----------------------- - Optimum 'visibility hours' from Yohkoh will be used in priority: Exemple of times of 1st pass at KSF are: Dec. 10 19:06 UT (noon at NSO/SP) Dec. 13 18:18 UT Dec. 16 17:31 UT (late morning at NSO/SP) These times are the starting times of the most interesting sequences to be performed on Yohkoh; up to 6 hours of data can be collected with interruptions due to the orbital motion. - Weather permitting, at least 2 hours of uninterrupted observations will be collected at NSO/SP. - On SoHO, the minimum request concerns: with EIT: 2 hours of uninterrupted observations in 2 slots, from 17 to 18:00 and from 19 to 20:00 UT with SUMER: 3 hours of uninterrupted observations from 17 to 20:00 UT Important Notice: ---------------- Dates of the 1st run: dec. 10 to dec. 17 included, 1996. The best time for seing quality is from UT 16:00 to 19:00 at NSO/SPO (Observation is scheduled). K-line G-B filtergrams will not be collected at NSO/SP on dec. 14-15. It is anticipated that a real time connection between the 3 different sites where observations will be collected (ISAS; EOF/ GSFC and NSO/SPO) will allow an increasingly interesting targeting of solar sites with the much appreciated help of Observers and Operators. contact person(s): ------------------ koutchmy@iap.fr bocchialini@ias.fr vial@ias.fr boudine@ias.fr delannee@iap.fr shibata@spot.mtk.nao.ac.jp -------------------------------------------------------------------------