Hi guys, the planetarium items can also be found in error room. Run with Azazel on hard, chest, telepills to the error room! I got the Pluto item on Caves 2 13:29, 28 December 2016 (UTC)Slowpiou

Not sure what chest you meant, but I AM ERROR room contains almost all items so no need to specify it.
Kator278 (talk) 13:47, 28 December 2016 (UTC)
Yes, I noticed. It was the chest floor and the item was on a pedestal. But maybe the item spawn because it is the chest floor... I don't know if we can find a planetarium item in the floor 14:32, 28 December 2016 (UTC)Slowpiou
At least so far I haven't seen that yet. Actually the most exact way to check if an item is in some pool is using an unpacker to get Itempool.xml file. However there's no such unpacker works with Antibirth. So only specify the item pool which is already confirmed.
Kator278 (talk) 21:11, 2 January 2017 (UTC)

Questions, Observations

So Ive been doing Purist runs for a while now and I have a couple of observations/questions regarding this room

Picking up item from the Planetarium or pressumably going on to it works the same way as going into Treasure room and removes the chance for next Planetarium to appear/resets it back to 0? I had 2 runs where I got it on floor 2 and I couldnt make it appear up to Depths 2. Even if it was 60% chance after reseting seem unlikely not to see one.

This one is continuation from the previous: Planetariums can only appear on floors where Treasure rooms are suppose to appear? As in not in Womb+. If you got one on Cellar 2 you would be guarenteed one at Womb II + (5x20% chance after 5 floors)

This is minor but: Planet items are way more likely to appear in planetariums than Zodiac Items? I visited 8 of them so far, got all but 1 Planet item with the help of d6 and I never had Zodiac appear instead of Planet item. 20:52, 30 December 2016 (UTC)

Actually I don't know the concrete condition of how a Planetarium room respawns... Also wiki has 2 versions of Treasure Rooms' skipping that are totally different, but which one is true, I have no idea...
For Zodiac/Planet item things, it seems more like randomly since I can meet Planets normally and not rarely.
Kator278 (talk) 21:11, 2 January 2017 (UTC)