The UP Astrosoc Headquarters or Tambayan ("literally place for loitering")

UP Astrosoc's headquarters is at the old planetarium of the PAGASA Astronomical Observatory in UP Diliman. It is located down the steps from the observatory.

UP Astrosoc is allowed use of the old planetarium for its storage. it houses the library and the equipment (astronomical and otherwise) that the organization possesses.

The covered porch at the top of the tambayan which we call the moondeck also serves as a meeting place for meetings and Lectures.

There is also a grassy field at the foot of the observatory which UP Astrosoc uses for observing. It has a good view of the northern and eastern skies. Occasionally, Astrosoc uses the much bigger sun deck at the top of the PAGASA office for use.