Many accepted abbrevations are used in Astronomy, here are some of them:
ADU: Pixel Value (analog-to-digital unit)
APO: Apochromatic refractor
AAPOD: Amateur Astronomy Picture of the day
APOD: Astronomical picture of the day (website)
APT: Astrophotography tool (capture software)
AU: Astronomical Unit (distance from Earth to the sun)
Bahtinov mask: A patterned mask put in front of the aperture to aid focus. Invented by Pav Bahtinov who didn't patent it!!!
Bayer: Bayer is the name of the person who invented the Bayer pixel pattern that is in every DSLR. It has groups of four pixels in a square and is configured R,G,G,B so you get twice as many green as red or blue. The camera software decodes all this and you get a normal looking colour picture.
Bias: Very short image possibly 0.001 secs taken with the lens cap on. Used for calibrating certain noise in astro-images.
Binning: Binning is the combination of two or more CCD image sensor pixels to form a new “super-pixel” This improves signal to noise ratio SNR, allowing exceptional quality image recording, at extremely low light levels.
Bins: Binoculars
CCD: Charge-Coupled Device, generally referred to in Astro-imaging as dedicated cooled cameras.
CME: Coronal mass ejection
CMOS: Complementary metal–oxide–semiconductor (type of camera sensor). There are now cooled CMOS cameras available for Astrophotography of DSOs. These require shorter images but in total about the same amount of time spent as CCD camera images. But they run less risk of place trails ruining a long image, or guiding issues are reduced.
Dec: Declination, the astronomical equivalent to latitude
Differential Flexure: Slight movement between a guidescope and an imaging scope.
Dithering: A method of moving your image by a few pixels between exposures in order to reduce noise and hot pixels by overlapping. Normally operated on software which will speak to the guiding software.
Dob: Dobsonian telescope
Drizzle: Increases the resolution for small objects. It is memory hungry so select small area.
DSLR: Digital SLR camera (Single lens reflex)
DSO: Deep space object
DSS: Deep Sky Stacker, free stacking software
Ecliptic: The path that the Sun Moon and planets move along in the course of a 24 hour rotation. Also the plane of the solar system.
EFW: Electronic filter wheel
EP: Eyepiece
FF: Field Flattener. Optical lens for correcting curvature in an image and helps alleviate comet shaped stars in the corners provided the right spacing is used.
Flats: (Or flat fields). Images of the light train through the scope and camera.
Focal Ratio: The focal length divided by the aperture.
FOV: Field of view
FR: focal Reducer
GEM: German equatorial mount
GMT: Greenwich meantime
Guiding: Using a 2nd camera and scope to correct tracking during imaging.
Ha: Hydrogen alpha, often used to denote typed of filter used.
HaLRGB: Image using hydrogen alpha, Luminance, and RGB
Hartmann Mask: Another focusing tool, like a Bahtinov Mask using 3 holes
HDR: High Dynamic Range
HOO: Hydrogen Oxygen and Oxygen ( a combination in a bicolour narrowband image)
Hubble Palette: This is a term applied to narrowband imaging where Ha is used in the green channel, Sii is used in the Red Channel, and Oiii is used in the blue channel. This creates the blue and yellow images seen.
IR: Infrared
ISO: Sensitivity to light by an image sensor
ISS: International space station
LMG: Large Magellanic cloud
Looping: Repeated short images which give a sort of "live view" effect in CCD cameras.
LP: Light Pollution
LRGB: Luminance, Red, Green and Blue filters
LX: Long Exposure
Mak: Maksutov cassegrain telescope
Meridian: Imaginary line that runs north to south overhead
Mono: Black and white image or B&W camera
NEO: Near Earth object
NGC: New general catalogue
OAG: Off axis guiding
Oiii: Normally refers to Oxygen filter
OSC: One shot colour (camera)
OTA: Optical tube assembly
PA: Polar alignment
PE: Periodic error in a mount is caused by imperfections in the gear train
PEC: Periodic error correction
PHD: Guiding software (Push Hard Dummy)
PI: Pixinsight
PN: Planetary nebula
POD: Personal Observatory Dome
PS: Photoshop
PST: Personal Solar telescope
RA: Right ascension, the Astronomical equivalent to Longitude
RC: Ritchey-Chretien Telescope
RDF: Red dot finder
Register: Align the images so that they exactly match. Normally done by aligning the stars.
RGB: Red, Green, Blue
ROR: Roll off roof
SCT: Schmidt Cassegrain Telescope
Sii: Normally refers to Sulphur filter
SMG: Small Magellanic Cloud
SNR: Signal to noise ratio
UFO: Unidentified flying object
UT: Universal time