Nebulae Near the Hot Wolf-Rayet Star BAT99-2 in the LMC

Three-colour composite image of the highly excited nebula near the Wolf-Rayet (WR) star BAT99-2 in the Large Magellanic Cloud (LMC), obtained in January 2002 with the FORS1 multi-mode instrument at the 8.2-m VLT MELIPAL telescope at the Paranal Observatory (Chile). It is based on three exposures through narrow-band optical (interference) filters that isolate the light from specific atoms and ions. In this rendering, the blue colour represents the light from singly ionized Helium (He II; wavelength 468.6 nm; exposure time 60 min), green corresponds to doubly ionized oxygen ([O III]; 495.7 + 500.7 nm; 5 min) and red to hydrogen atoms (H; H-alpha line at 656.2 nm; 5 min). Of these three ions, He II is the tracer of high excitation, i.e. the bluest areas of the nebula are the hottest. The sky field measures 400 x 400 square arcsec; the original pixel size on the 2k x 2k CCD is 0.23 arcsec. North is up and east to the left. Before combination, the CCD frames were flat-fielded and cleaned of cosmic-rays. Moreover, the stars in the blue (He II) image were removed in order to provide a clearer view of the surrounding nebular emission. The reproduced brightness is proportional to the square-root of the actual intensity; this increases the "dynamical range" of the image, i.e. it shows better areas of very different brightness.

Credit:

ESO

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About the Image

Id:eso0310b
Type:Observation
Release date:9 April 2003
Related releases:eso0310
Size:1200 x 1195 px

About the Object

Name:BAT99-2, LMC
Type:• Local Universe : Star : Type : Wolf-Rayet
• Local Universe : Star : Grouping : Binary
• Local Universe : Nebula
• X - Nebulae
Distance:180000 light years
Constellation:Dorado

Image Formats

Large JPEG
671.1 KB
Screensize JPEG
401.6 KB

Wallpapers

1024x768
401.5 KB
1280x1024
599.2 KB
1600x1200
759.0 KB
1920x1200
787.7 KB
2048x1536
1.0 MB

Coordinates

Position (RA):4 49 35.71
Position (Dec):-69° 20' 48.88"
Field of view:6.65 x 6.62 arcminutes
Orientation:North is 0.0° right of vertical
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Colours & filters

BandWavelengthTelescope
Optical
Heiii
468 nm Very Large Telescope
FORS1
Optical
Oiii
495 nm Very Large Telescope
FORS1
Optical
Oiii
500 nm Very Large Telescope
FORS1
Optical
H-alpha
656 nm Very Large Telescope
WFI

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