AO21 is open and solicits proposals for observations to be carried out in 2024. The letter from ESA's Director of Science, inviting you to participate in the 21^st Call for Proposals, is available here.

Since this is the last AO, proposals may compete for unique use of INTEGRAL capabilities*. We thus encourage clear arguments why only INTEGRAL can achieve the proposed science goals. Also encouraged are still new ideas from outside the INTEGRAL community. If there are doubts about feasibility, proposers are encouraged to consult the INTEGRAL Helpdesk.
*Examples of unique INTEGRAL capabilities are:

• Covering large fractions of the sky from 3 keV to 10 MeV
• Long (days) uninterrupted observations.
• Arcminute spatial resolution at 20-1000 keV (IBIS)
• keV spectral resolution at 20-8000 keV (SPI)
• imaging soft gamma-ray polarimetry (IBIS/SPI)
• unique sky coverage (nearly omni-directional detector shields + long orbit), complemented by coverage in X-rays (3-35 keV, JEM-X) and optical (500-600 nm).

Approximately 13 ESA Fellowships will be offered this year in Space Science, for a maximum of three years (two years + extension requiring a dedicated proposal).
For full call info visit: https://cosmos.esa.int/web/space-science-faculty/opportunities/research-fellowships
Application deadline: 18 September 2023.