contest winners

CONTEST WINNERS
JANUARY 2002

Imaging Category:

Roland Christen
AstroPhysics

Science Category:

Arto Oksanen
Nyrölä Observatory

Roland Christen submitted this interesting and highly detailed image of the core of M42 showing the Trapezium and surrounding nebulosity. The image is noteworthy not only for its resolution of the trapezium stars, but also for the excellent display of the great dynamic range included in the whole frame. The trapezium area is on the order of 100X brighter than the dark red areas of the image.

Jan_M42LRGB10Maksm3_Roland_half.jpg (109421 bytes)

Trapezium and surrounding nebulosity at the core of M42 by Roland Christen

"The final image consists of 3 sets each of LRGB images of 10, 60 and 300 sec duration. The shorter exposures were blended on top of the longer ones to allow the outer portions of the nebula to be seen without burning in the inner detail. All the images were taken with 2x2 binning using the ST10E camera, CFW, AP 10" F14.6 Mak-Cassegrain at prime focus, mounted on an AP1200 mount. The images were captured using CCDOPS. Initial alignment and stretching was done in MaximDL. Final stacking and color processing was done in Photoshop using layers."

Arto Oksanen submitted the first ever amateur observation of an extra solar planet transit over star HD209458. The team was able to measure a change in brightness of the target star of 0.02 magnitudes.

Final lightcurve of the September 16, 2000 transit.
HD209458 is on the top and below is one of the reference stars offset by 0.05 magnitudes.

"Our observation was performed at Nyrölä Observatory in Finland on the night of September 16, 2000 by amateurs of astronomy club Jyväskylän Sirius. Equipment used: 16-inch Meade LX200 telescope on equatorial mount, ST7E CCD with photometric V-filter, Meade f6.3 reducer.

We started the observing run at 20.33 UT when there was about one hour to the beginning of transit by the prediction published on exoplaners.org web page. Even though the star is too dim to see on naked eye it was very bright object for CCD-imager and limited the exposure time to just 10 seconds even though the image was defocused to spread the light on several pixels. We logged about four images per minute and continued observing for next four and half hours to record a full transit.

From the individual images the dimming caused by the planet was not measurable. The measurement errors were far larger than the magnitude drop. All 866 images were carefully calibrated and each star was measured with IRAF software. Still the transit was not visible even though the preliminary lightcurve showed some indications of it. Only after all measurements of each 10 minute timeslot were averaged the transit became very obvious on the lightcurve. The transit times agreed very well with the prediction and observed magnitude drop on V-band was 0.02 magnitudes. Still the errors are quite large, but now less than the observed magnitude drop. One of the field stars was used to check the measurements and its magnitude remained constant (within errors) during the transit."