SUMER First Images

First Images observed by SUMER 24./25.Jan.96

According to the information gathered in the FITS files, on the 24th of January 1996 at 18:48 UT the first Solar EUV light hit a SUMER detector. SOHO was still on the way to its destination L1 point. During the testing phase, SUMER's detectors were switched on and the door was opened. The telescope, focus and scan mirror were still in the process of being adjusted. It has to be noted, too, that the detector gain was adjusted afterwards, so the image above does not show SUMER's full spectroscopic capability.

Ultraviolet light in the range around the Oxygen VI emission line at 1031.9 Å (Transition Region, 300 000 K temperature) fell through the 0.3*120 arcsec² slit onto the middle part of detector B that was exposed for 60 seconds. The telescope was pointing to the north Solar limb. - The figures above show the spectral image and the resulting profiles.

On the next day, a first Solar test scan was performed in the same wavelength and the same area with the same slit:

SUMER study: Detector B first light, limb scan

date, time: 25.Jan.96, 10:44 - 10:51 UT
field of view: 59 arcsec E - 59 arcsec W, 924 arcsec N - 1004 arcsec N
slit: 0.3 arcsec x 120 arcsec, centered (number 7)
raster step size: 0.75 arcsec (2 elementary steps)
exposure time: 2.5 seconds
telemetry: 159 images of 25 spectral x 120 spatial pixels (format 14)
compression: quasilog-min-max (method 5)
wavelength: 1031.91 Å on reference pixel 500 of Detector B
rotation compensation: standard
binning: no spectral, no spatial
on-board flat field correction: no

Remarks: Since the study was executed early in the commissioning phase, the real field-of-view coordinates may not be as commanded. - The scan was preceded by several 2-min.-exposures in various wavelengths at the same coordinates.

There was an earlier version of this page.

Spectral window

Average detector image, average profile.

O VI 1031.9 (300 000 K)

Line intensity, shift and width.

IED, 10.Nov.98