You can use your Observatory to peer into the far corners of Wildspace and the Astral Plane. After spending a Long Rest in your Observatory, you gain a magical Charm (see "Supernatural Gifts" in chapter 3) that lasts for 7 days or until you use it. The Charm allows you to cast Contact Other Plane without expending a spell slot. You can't gain this Charm again while you still have it.
Observatory Charm
RewardXDMGp. 3432024
Raw data
{
"name": "Observatory Charm",
"page": 343,
"type": "Charm",
"__prop": "reward",
"source": "XDMG",
"entries": [
"You can use your Observatory to peer into the far corners of {@book Wildspace|XDMG|5|Wildspace} and the {@book Astral Plane|XDMG|5|Astral Plane}. After spending a Long Rest in your Observatory, you gain a magical Charm (see \"{@book Supernatural Gifts|XDMG|2|Supernatural Gifts}\" in {@book chapter 3|XDMG|2}) that lasts for 7 days or until you use it. The Charm allows you to cast {@spell Contact Other Plane|XPHB} without expending a spell slot. You can't gain this Charm again while you still have it."
],
"additionalSpells": [
{
"innate": {
"_": {
"limited": {
"1": [
"contact other plane|xphb"
]
}
}
}
}
]
}