First Results From SPICE EUV Spectrometer on Solar Orbiter

SPICE (Spectral Imaging of Coronal Environment) is an EUV imaging spectrometer onboard Solar Orbiter. SPICE observes the Sun in two wavelength bands: 69.6-79.4 nm and 96.6-105.1 nm and is capable of recording full spectra in these bands with exposures as short as 1s. SPICE can measure spectra from the disk and low corona, and records all spectral lines simultaneously, using one of three narrow slits: 2”x11’, 4’’x11’, 6’’x11’, or a wide slit 30’’x14’. The primary mirror can be scanned in a direction perpendicular to the slit, allowing raster images of up to 16’ in size.

The first SPICE data were taken during the instrument commissioning carried out by the RAL Space team between 2020 April 21 and 2020 June 14, and at the first Solar Orbiter perihelion at 0.52AU between June 16-21.  We give examples of full spectra from the quiet Sun near disk centre and provide a list of key spectral lines from neutral hydrogen and ions of carbon, oxygen, nitrogen, neon, sulphur and magnesium. These lines cover the temperature range between 10,000 K and 1 million K (10MK in flares), providing slices of the Sun’s atmosphere in narrow temperature intervals. We show examples of raster images in several strong lines, obtained with different slits and a range of exposure times between 5s and 180s.

We have found several unusually bright, compact structures (named “beacons”) in the quiet Sun network, with extreme intensities up to 22 times greater than the average intensity across the image. The lifetimes of these sources are longer than 1 hour. We will derive plasma velocities in the beacon area, and co-align the SPICE rasters with the SDO/AIA 304 and 171 images and the HMI magnetic field to better understand the origin and properties of beacons.

We also show the first above-limb measurements with SPICE in Mg IX, Ne VIII and O VI lines, as obtained when the spacecraft pointed at the limb. Maps of Mg/Ne abundance ratios on disk can be derived and compared with in situ measurements to help confirm the magnetic connection between the spacecraft location and the Sun’s surface, and locate the sources of the solar wind.