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Old 15-04-2011, 07:25 PM
timokarhula (Timo)
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Join Date: Nov 2010
Location: Sweden
Posts: 10
Brian Skiff of Lowell Observatory gives here some further advice how to image the LMC Light Bridge.

"A couple of points to mention in regard to picking it up
both visually and photographically. The best time for viewing is
at around sidereal time 12h, when the LMC is over in the west and
the galactic center is rising in the east. Look along the line
between the two, which goes beneath the Milky Way.
For imagers:

1) It is worth emphasizing that the feature is very large,
and of low (but not especially low) surface brightness,
about like that of the zodiacal band on either side of the
Gegenschein. Thus the camera lens should be stopped down to
avoid vignetting.

2) In addition, imagers are fond of processing their results
to "flatten out" such large scale features --- obviously you will
miss it if you apply any cosmetic processing of this sort:
turn off that button in your software!

3) Another point is to use a filter or do whatever is necessary
to avoid picking up the night-airglow pattern; if the detector is
sensitive in the far-red, this could swamp the "light bridge".
The goal would be to record only in the visual (or blue-green-yellow)
range of wavelengths, _excluding_ H-alpha and redder."

/Timo Karhula
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