Common Abbreviations and Terms

This is where you can read up the answers to some FAQs on astronomy and star-gazing in Singapore. Members' contributions are welcomed.
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Common Abbreviations and Terms

Postby Gary » Sun Mar 18, 2012 4:26 pm

Hi Friends. If such a list has been compiled before, please let us know so that this can be merged with it.


Common Abbreviations and Terms used in this forum

Please take note some of the abbreviations and terms in this list are quite international across astronomy forums while others are quite colloquial. The main purpose is to convert a cryptic-sounding term to a more meaningful and searchable English term.

(1) Equipment

OTA --- Optical Tube Assembly. Meaning the telescope itself only, no finder/tube rings/diagonals and other accessories.
AZ --- Alta-azimuth system or tripod mount.
EQ --- Equatorial system or tripod mount.
EP --- Eyepiece.
FL --- Focal Length.
FOV --- Field of view. The diameter of the circled field of view when you look through an eyepiece.
AFOV --- Apparent Field of View. A specification of an eyepiece to illustrate how wide a field of view it can offer.
TFOV --- True Field of View. The actual field of view when a particular eyepiece is used on a particular telescope.
Grab-and-Go --- A telescope setup where it is light and portable enough to bring along to other places.
Dob --- Dobsonian system. Usually refers to big reflector telescopes made famous by John Dobson.
Mak --- Maksutov telescope design.
MCT --- Maksutov–Cassegrain telescope design.
MN --- Maksutov-Newtonian telescope design.
Newt --- Newtonian reflector telescope design.
SCT --- Schmidt–Cassegrain Telescope design.
CATS -- General classification of all types of cassegrain related telescopes. E.g. MCTs and SCTs.
PTV or PV --- Peak to Valley. A measurement of quality of optics.
Wave --- Short for Wavefront. A measurement of quality of optics.
Achro -- Achromatic design.
APO -- Apochromatic design.
ED -- Extra Dispersion.
Doublet -- One 2 lens element. Usually refer to refactor telescope and some eyepiece lens design.
Triplet -- One 3 lens element. Usually refer to refactor telescope and some eyepiece lens design.
CA or False Colour -- Chromatic Aberration.
Bino -- Short for Binocular or the Binoviewer accessory for telescope.
CW --- Counter-weights. For balancing purposes in an equatorial telescope setup.
RACI --- Right Angle Correct Image. Usually for describing finder scope views where the view looks "normal" - not inverted vertically or laterally.
RDF --- Red Dot Finder.
Telrad --- A zero-magnification finder with illuminated circles projected on a piece of glass.
RA --- Right Ascension.
DEC --- Declination.
FMC -- Fully Multi-Coated.

(2) Astrophotography

AP --- Astrophotography
Imaging --- Taking photos and videos
Stacking --- Combining various photos of the same object as one photo. Usually via software to improve image quality and reduce image noise.
PEC --- Periodic Error Correction. A system to counteract tracking mount worm gear errors to prevent star/object trailing and improve photographs.

(3) Locations

ECP ---East Coast Park. Also name of a major expressway.
SSC --- Singapore Science Centre.
Causeway --- Bridge linking Singapore to Western Malaysia.
MP --- Marine Parade.
TP --- Tampines.
TPY - Toa Payoh.
AMK --- Ang Mo Kio.
MB --- Marina Barrage.
MBS --- Marina Bay Sands. Integrated Resort.
RWS --- Resort World Sentosa. Integrated Resort.
Kino --- Kinokuniya Book Store which has one of the largest selection of astronomy books. Usually referring to main branch at Takashimaya at Orchard Road.
Woodlands CIQ --- Custom checkpoint at Woodlands, Singapore. The only train station in Singapore after closure of Tanjong Pagar train station. Train tickets to Malaysia can be purchased here offline.
AYE --- Ayer Rajah Expressway
BKE --- Bukit Timah Expressway
CTE --- Central Expressway
ECP --- East Coast Parkway
KJE --- Kranji Expressway
KPE --- Kallang-Paya Lebar Expressway
MCE --- Marina Coastal Expressway
PIE --- Pan Island Expressway
SLE --- Seletar Expressway
TPE ---Tampines Expressway

Sedili --- Dark sky location in the state of Johor, Western Malaysia.
Punggai --- Dark sky location in the state of Johor, Western Malaysia.
Mersing --- Dark sky location in the state of Johor, Western Malaysia.
Kahang --- Dark sky location in the state of Johor, Western Malaysia. Not to be confused with the state Pahang.
JB --- Johor Bahru. Southern tip of Western Malaysia. Please take note Johor Bahru is *part* of Johor. Not *all* of it. :)
Kampung/Kampong --- Village. Usually rural.

(4) Celestial Objects

M1, M2, M3, ...etc --- Listed of objects compiled by famous french astronomer Charles Messier where M represents Messier. [Link]
C1, C2, C3, ...etc --- List of objects complied by Sir Patrick Caldwell-Moore. C represents Caldwell.[Link]
NGC XXXX --- Celestial objects listed in the New General Catalogue
Neb --- Short for Nebula
GC --- Globular Star cluster
DSO --- Deep Space Objects. Usually dim but some of them can be relatively bright.
Doubles --- Two stars very close to each other.
Deg ' "" --- Angular measurement of degree, arc minutes and arc seconds respectively.

(5) Equipment Brands

Tak --- Takahashi
TV --- Televue
AP --- Astro-Physics
SV --- Stellavue
ES --- Explorer Scientifc
AT --- Astro-Tech/Astronomy Technologies
JMI --- Jim's Mobile Inc.

(6) Misc

Ob --- An observation session.
Ob Site --- An observation site.
Sidewalk --- Free and open-to-public session conducted at populated urban areas for the main purpose of sharing the wonders of the universe with the public through telescopes/binoculars/video screens/astronomical printouts.
CN --- Cloudynights Astronomy forum and classfieds in United States
A-mart --- Astromart astronomy forum and classifieds in United States.
M0 --- Messier object zero. :P

.... More to come and will re-list them in a better format as more entries are entered. Feel free to contribute by replying to this thread.
email: gary[at]
twitter: @astrosg

"The importance of a telescope is not how big it is, how well made it is.
It is how many people, less fortunate than you, got to look through it."
-- John Dobson.

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