HUT Observatory

Sister Observatory in Suburban Massachusetts Experiements with Narrow-Band Imaging

The Rosette Nebula in the winter constellation Monoceros as recently imaged at our sister facility in Massachusetts, Yellow House Observatory, by David Mittelman.

The Rosette Nebula, NGC 2237, in Monoceros.

Yellow House Observatory in Dover, Massachusetts, is a sister facility to HUT Observatory and is operated by David Mittelman.  After long efforts to commission a photographic system there, exciting results are appearing.  The featured image on our homepage shows the Rosette Nebula in the winter constellation Monoceros.  The nebula was recorded by Mittelman with a Takahashi refractor and SBIG STL CCD 11000 camera, mounted with a PlaneWave 17-inch CDK telescope on a Paramount ME equatorial.  The image is a combination of four 15-minute exposures made through a narrow-band filter in the red light of the hydrogen-alpha spectral line.  Celestial nebulae like the Rosette glow most brightly in the several natural colors of energized hydrogen, the brightest of which is a particular red of wavelength 6563 ångstroms.  The electronic camera is equipped with a filter wheel allowing remote control of the color selection.  The entire Yellow House Observatory system, in fact, can be controlled over the Internet, and in some respects Yellow House is a testbed for advanced control software that will soon enhance operation at HUT Observatory in Colorado.

The Rosette Nebula is east of the bright winter constellation Orion, and it is centered on a cluster of hot, blue stars called New General Catalogue 2244.  While NGC 2244 is easily visible in binoculars, the surrounding nebula is difficult in part because human eyes are less sensitive to faint red light than to other colors.  The distance to the object is about 5,000 light years, and the diameter of the nebula is about 130 light years.  The star cluster has formed from the gas cloud and is now serving to energize and compress it, causing ongoing star formation inside the nebula.  In some areas, the nebula is so hot that it’s emitting X-rays.

calibrated Horsetest2 with Dennis

The region of the Horsehead and Flame Nebulae near the bright easternmost belt star Alnitak in Orion.

Another target recently recorded at Yellow House is the famous Horsehead Nebula in Orion, also known as Barnard 33.  This wide-field view, recorded with the same equipment used for the Rosette Nebula above, shows the dark Horsehead as a small silhouette near the center of the frame.  The Flame Nebula, NGC 2024, is the bright complex at the lower right, cut with dark bands of dust and unilluminated gas.  A star to the left of the Flame Nebula is actually the bright, blue, naked-eye star called Alnitak that is easternmost in the Orion constellation’s famous belt.  Normally its brightness overwhelms celestial photography of the region, but because the Yellow House setup can use a hydrogen-alpha filter, Alnitak’s apparent brightness is reduced in this image.  Most of the nebulosity seen in this region is about 1,000 light years away from Earth.  The famous, bright Great Orion Nebula is not too far outside the field of view.  (Note that south is up in the orientation of this image.)

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Thor’s Helmet, a nebula 15,000 light years distant in the winter constellation Canis Major.

A final recent photo from Yellow House reveals an object called Thor’s Helmet, also in our winter sky in the constellation Canis Major.  At a distance of about 15,000 light years, NGC 2359 is much farther away than the other clouds recently imaged, but it remains a spectacular photographic target in the red light of hydrogen.  This view is the superposition of two 15-minute-long exposures, a process that reduces noise in the resulting final image.  During the exposure sequence, it’s necessary for the telescope to track the sky with rather amazing accuracy.  In the case of the 60-minute total exposure for the Rosette Nebula above, the telescope tracked an arc about 15 degrees long, with profound steadiness.  The ultimate success of the Yellow House Observatory installation is due much to the engineering skill of Alan Sliski of Lincoln, Massachusetts, who, with his sons, has been involved with many research and academic observatories in the Northeast.  Dennis di Cicco, a renowned local astrophotographer and astronomy journalist, has advised regarding imaging technique.  Among key software tools are CCDStack from CCDWare and the telescope control suite SkyX Pro from Software Bisque.