|
In order to support remote observations, we set up an All-Sky camera which continuously monitor the
night sky from dusk to dawn. This enable observer to follow the sky conditions on a remote location
in real time. As a by-product, the camera records various transient phenomena like meteors, fireballs, auroras,
aircraft and satellite passes. Since the camera limiting magnitude on a moonless night is about 5.5,
it can also record outbursts of bright Novae. It is in regular operation since August 2004.
Our first camera setup (in operation from August 2004 until 25. May 2006) consist
of a fast 115mm diameter, f/0.3 concave mirror, giving a 180o field of
view from a distance of about 0.5 m. This was replaced with a 150 mm convex mirror with a high
quality coating (90%) which enable detection of fainter stars and moving objects. The
imaging device is a SBIG ST-7XMEI CCD equipped with a wide-field 2.8/16mm f.l. lens. CCD sensor
is KAF-0402XME with 9 micron pixels and microlensing technology yielding a 85% QE at 650nm.
Camera setup effective focal length is 2.5 mm. Image resolution is about 15'/pixel. Typical camera exposure time on a moonless night is 60s.
It is further automatically reduced according to sky brightness conditions due to twilight and
presence of Moon.
ST-7 CCD camera has a high speed USB interface with 1 second full frame download time. Therefore,
only 1-2% of night time is missed due to image download.
The imaging system is run in Linux, using Tserver software that we use on other telescopes. Images are
bias and dark subtracted immedeately after exposure is taken.
They are stored in FITS format and after some time archived on a DVD. A MPEG/AVI movie is
automatically composed after each observing session and posted on a public accessible all-sky
camera archive .
Movies are not of a high quality due to a limited disk space. However, they are good enough to see
many interesting phenomena and obtain an impression about the quality of particular night.
List of interesting events
is posted on a separate page, together with JPEG and original gzipped FITS files.
Bright fireball, apparently from Perseid radiant was
recorded over the eastern horizon on a 60 second exposure taken on 2004 Aug 16 at 22:12:49UT (center).
Please note that all materials are subject to copyright conditions.
We are thankful to Edo Smolnikar of the Tehnooptika Smolnikar d.o.o. in Ljubljana for donation of several off the shelf
concave mirrors - key components for making All-sky cameras.
|
