M 20 - THE TRIFID NEBULA

Sagittarius

(ra: 18,02.6 / dec -23:02)

DATA

TYPE: Emission and Reflection Nebula

VISUAL BRIGHTNESS: 9

SIZE: 29 x 27 arcs minutes

DISTANCE: between 2200 and 6000 light years

OBJECT DESCRIPTION

M20 is one of the atractions of the southern winter sky. It can be easyly seen with 7x50 binoculars  even in relatively light poluted skyes.  Its name came out of the redish three lobed apearence which are inoized from the central star HN 40, a sextuple star system. Charles messier described it as a cluster of stars of 8 to 9 magnitude surounded by nebulosity in 1764.

IMAGE INFORMATION

SCOPE: Orion ED 80 @ f7.5

MOUNT Vixen GPDX mount with Sky Sensor 2000

SKY CONDITIONS: visual limit magnitude 4. Seeing Tansparency Regular

CAMERA: Starlight SXV M7

FILTERS: Astronomik Type II

EXPOSURES: LRGB (64,16,16,16) 240 seconds subs

GUIDING: Synta 70/300 Refractor. SXV Guide Head

IMAGE ADQUISITION: Astro Art and CCD Control Interphase 3.71

CALIBRATED: Darks, flats, offset in ImagesPlus PROCESSING: Photoshop CS