So ... updates are needed to some of the categories again after part II of the exploration trip found here: https://forums.frontier.co.uk/showthread.php?t=66655
Hottest star: HD 154873 C with 4,910,023.00K
Hottest non-neutron star: HD 148937 with 103,964.00K
Coldest Star: AUCOKS JA-B A13-6 with 283K
Highest planet pressure: HD 148937 8 with 655,836,008 atmospheres
Highest planet temperature: HD 148937 5 with 17,614K