The Sun in Ne VIII (plus Details)

The Sun in Ne VIII, observed by SUMER 02.Feb.96

[Full Picture]

The Sun seen in the emission line of Neon VIII at 770.4 Å (corona, temperature 600 000 K). The picture was put together from eight horizontal raster scans in alternating directions and of different length, starting in the solar SE. Each raster scan includes 664 to 1074 exposures, lasting 7.5 seconds each. The picture is shown in bins of 3x3 pixels, one pixel being approx. 1 arcsec².

Some image corrections were performed and most data faults were eliminated by replacing them with the average of their neighbors (approx. 4 per 1000 raster steps).

The brightest pixels in this picture correspond to an intensity of approx. 260 counts/line/arcsec² whereas the intensity is generally below 40. The average intensity on the disk is around 6.

Details

(intensities not on same scale)

[Prominence] Prominence at NE limb

[Loops] Loops near W limb

Spectral window

Shown is the spectral window on the detector (left), averaged over one horizontal scan, and the average profile of the Ne VIII line (right).

In the 25(spectral)x360(local) pixels selected and transmitted from the 1024x360 detector plane of the spectroscope, the image of the 300x1 arcsec² slit can be observed, covering 301 local pixels in N-S-direction plus some stray light. The spectral pixels correspond to 0.0211 Å (2nd order). The profile shows counts/pixel/s versus wavelength in Å.

Images in higher resolution

The 3x3 binning does not demonstrate SUMER's full resolution capacity. The following quarters (approx. 600 KB each, without binning) and another full disk image (832 KB, binned twice) can be