The target - H1821+643 - is being observed by ACIS-S for 13 hours and 53 minutes. The observation started 8 hours ago and ends in 6 hours, and is part of the proposal Compton cooling of the hot cluster atmosphere beneath the low-redshift quasar H1821+643. The target - also called 2XMMi J182157.2+642036 - is located in the constellation Draco and is a Seyfert 1 Galaxy. The source is so bright in X-rays that only one-eigth of the chip is used for the observation. More information on the target can be found at SIMBAD. See related observation: 22105.