Why does it have to be some dedicated astro product ( which means expensive)? There are plenty of wifi AC switch units on the market. One unit can switch on a power board. As he is powerung a home observatory it probably has AC anyway.
Something like this,
https://www.google.com.au/search?q=w...TkRDOsQgjYI-gQ
Or this from Jaycar
https://www.ebay.com.au/p/240v-Mains...9451e8fffd11af