1. Sunspot Studies in Oslo Nils Brynildsen, Per Maltby, Terje Fredvik and Olav Kjeldseth-Moe Institute of Theoretical Astrophysics University of Oslo

2. Program History Sunspot studies with SOHO instruments from 05/1996 Purpose: To study the transition region and corona above spots, particularly the fast down flows into sunspot umbrae observed with HRTS Extended to sunspot plumes, and 3 min oscillations in the sunspot chromosphere and transition region O_SPOT – studies run between May 1996 and present A total of 115 spots observed on 190 days All O_SPOT data are processed into intensity and velocity maps Results presented in papers, talks, posters and proceedings

3. Oslo Sunspot Studies O_SPOT1 – raster of (4) wide slit images at three wavelengths O_SPOT2 – limited spatial extent, but many lines, reasonably high cadence raster O_SPOT3 - coarse raster to replace O_SPOT1 O_SPOT4 - a “sit and stare” study for rapid time variations O_SPOT5 - large FOV, reasonable cadence, raster (incomplete area coverage, stripes) --------------------------------------------- O_SPOT10 – GIS study for sunspot oscillations O_SPOT11 – NIS study for sunspot oscillations

4. Oslo Sunspot Studies (2) Study Spectro- Slit Step Number of FOV of Exp. Cadence Name meter # size Locations/ one rst. time (duration) (as) Rasters (as^2) (s) (m:s) ============================================== O_SPOT1 NIS 6 50 4/4 240x240 10 2:04 O_SPOT2 NIS 4 2 60/1 120x120 20 22:36 O_SPOT3 NIS 5 8 30/1 240x240 8 6:20 O_SPOT4 NIS 3 drift 150/1 4x51 5 20:30 O_SPOT5 NIS 4 4 60/1 240x240 10 26:30 ---------------------------------------------------------------- O_SPOT10 GIS 2 drift 145/6 11x4 17 45:50 O_SPOT11 NIS 4 drift 250/1 13x120 10 60:00 ============================================== Studies marked drift have step size 0 arc-sec. and no rotational comp. Number of locations marks number of exposures defined as a single raster Solar drift rate x raster duration defines extent of raster in x-direction

5. Wavelength list Ion l (Å) T(K) #1 #2 #3 #4 #5 #10 #11 ===================================== He I 522 10 000 x He I 584 10 000 x x x x F x O III 599 95 000 x x x u O VI 554 175 000 x x x x l x O V 629 240 000 x x x x x l x Ne VI 562 430 000 x x x x Mg VIII 315 810 000 x G Mg IX 368 960 000 x x x x x I x Fe XIV 334 1 900 000 x S Fe XVI 360 2 700 000 x x x x

6. Number of spots/runs YearNumber of SunspotsNumber of days 1996 4 6 1997 8 24 1998 10 18 1999 20 30 2000 28 41 2001 23 36 2002 17 30 2003 5 5

8. - A 50 arc sec overlapping area, with ~30 s and ~2 min cadence - Clear and significant changes over 5 min time periods. Also perceptible changes over time spans of ~2 min.

9. - Mapping of plumes - Located above the white light spot - I > 5 x  i.e. yellow contour - Max visibility at 0.25 MK – do not occur in corona, i.e. cool - Down flows into the spots in TR - No corresponding up-flows - No systematic flows in corona - Up-flows in extended area? (large raster)

10. NIS Oscillations

11. GIS/NIS Oscillations

12. Data reduction of O_SPOT data All CDS data are corrected using standard CDS software, transformed to absolute intensity, and processed may encompass the following: -- Intensity and velocity maps from line profiles fitted to Gaussians. Blends removed before fitting. -- Routines for conditional probability analysis used on selected emission lines. -- Power spectra of relative integrated line intensities calculated for spectral lines to study the 3 minute oscillations. -- CDS data are often co-aligned and compared with data from SUMER, MDI or TRACE.