P
- P60 – (telescope) Palomar 60-inch telescope
- PA – (astrophysics terminology) Position Angle
- PAH – (astrophysics terminology) Polycyclic Aromatic Hydrocarbon
- PAMELA – (telescope) Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics, a space telescope used to study cosmic rays
- Pan-STARRS – (telescope) Panoramic Survey Telescope And Rapid Response System
- PASJ – (publication) Publications of the Astronomical Society of Japan
- PASP – (publication) Publications of the Astronomical Society of the Pacific
- PCA – (instrumentation) Proportional Counter Array, an X-ray detector on the Rossi X-ray Timing Explorer
- PCAS – (observing program) Planet-Crossing Asteroid Survey
- PDBI – (telescope) Plateau de Bure Interferometer, a radio telescope
- PDR – a photodissociation region or photon-dominated region (both terms are used synonymously); a region in the neutral ISM in which far-ultraviolet photons dominate the heating and chemistry
- PEP – (instrumentation) PhotoElectric Photometry, an observing technique using photometers
- PEPE – (instrumentation) Plasma Experiment for Planetary Exploration, an instrument on Deep Space 1
- PHA – (celestial object) Potentially Hazardous Asteroid
- PI – (person) Principal Investigator, the person who leads a scientific project
- PK – (catalog) Perek-Kohoutek, a catalog of planetary nebulae
- Planemo – (celestial object) Planetary Mass Object
- PLANET – (observing program) Probing Lensing Anomalies NETwork, a program to search for microlensing events
- PLS – (observing program) Palomar-Leiden Survey, a program to search for asteroids
- PMPS – (observing program) Parkes Multibeam Pulsar Survey
- PMS – (celestial object) Pre–Main Sequence, young stars that are still in the process of formation
- also pre-MS
- PMT – (instrumentation) PhotoMultiplier Tube
- P-L – a set of asteroid discoveries in the 1960s
- PN – (celestial object) Planetary Nebula
- also PNe (plural form of Planetary Nebula)
- PNG – (catalog) Galactic Planetary Nebula
- PNLF – (astrophysics terminology) Planetary Nebula Luminosity Function, the density of planetary nebulae as a function of their luminosity
- PNN – (celestial object) Planetary Nebula Nucleus, the central star in a planetary nebula
- PNNV – (celestial object) Planetary Nebula Nucleus Variable, a variable star in the center of a planetary nebula
- POSS – (observing program) Palomar Observatory Sky Survey
- PPARC – (organization) Particle Physics and Astronomy Research Council, a major government-sponsored science agency in the United Kingdom, merged into the Science and Technology Facilities Council in 2007
- PPM – (catalog) Positions and Proper Motions, a catalog of the positions and proper motions of stars
- PPN – (celestial object) Proto-Planetary Nebula, an object that has partially evolved from a red giant to a planetary nebula
- PRE – (astrophysics terminology) Photospheric Radius Expansion
- Proplyd – (celestial object) Protoplanetary Disk
- PSC – (catalog) Point Source Catalog, a catalog of point-like infrared sources detected with the Infrared Astronomy Satellite
- PSF – (instrumentation) Point Spread Function, a function that describes the blurring of a point source that is caused by the optics of the telescope and instrument (as well as other effects)
- PSI – (organization) Planetary Science Institute
- PSR – (celestial object) Pulsar
- PVO – (spacecraft) Pioneer Venus Orbiter
- PVTEL – (celestial object) PV TELescopii, a class of pulsating variable stars named after PV Telescopii, the archetype for the class
- PWD – (celestial object) Pre-White Dwarf, a star that no longer creates energy through fusion that will eventually evolve into a white dwarf
- PWN – (celestial object) Pulsar Wind Nebula
- PZT – (telescope) Photographic Zenith Tube, a general name for any telescope designed to observe objects passing at the zenith
Read more about this topic: List Of Astronomy Acronyms