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Mars/Mercury, Castor A/B & Regulus Spectra, Trapezium

Posted: 6 February 2013

The observatory was opened Tuesday, 5 February 2013, at 1806 MST, 69°F. Viewed Mercury at 1811 MST using 77X, 206X, and 364X. Mercury remains low in the sky but was better this night than on the previous night. Using 206X, a gibbous phase was visible. At 1817 MST, viewed Jupiter, 77X. Four moons were visible. At 1820 MST, viewed Mars and Mercury using 7x50 binoculars. Both were well in the same FOV. I then picked up both planets with the naked eye. Mercury was easy, but Mars was very difficult to see at 1820 MST.

This photo shows Mars (top) and Mercury (bottom), and was taken with the D7000 DSLR at 1842 MST, f/5.6, 1/20sec, ISO 400, 155mm.


At 1855 MST, I slewed the 8" LX200-ACF to Castor and began setting up for spectrum imaging using the D7000 DSLR and Star Analyzer. Due to the closeness and positions of Castor A and Castor B, using the "drift method" to acquire the spectral images was difficult. This is the unprocessed spectra from the Star Analyzer:


Castor A is the upper spectrum and Castor B the lower spectrum. By selecting the proper portions of the image, I was able to separate out the two stars:

Castor A - Spectral Type A1

Castor B - Spectral Type A2

I ended spectra imaging at 1954 MST, and since the constellation of Orion was well placed for viewing, I did an AutoStar tour of DSOs in Orion using 77X. Viewed the following nebulae: M42 (Great Orion Nebula), M43, NGC1977 (Running Man Nebula), NGC1990, NGC2024 (Flame Nebula), IC434 (Horsehead; yes, I saw it this night), and M78. I also viewed the open star cluster NGC2194.

I then did some high magnification (364X) viewing of the Trapezium star cluster. Six stars were visible. This image (cropped from full-frame) with the D7000 DSLR at prime focus + 3X TeleXtender, 20 second exposure, ISO 800, shows the six stars:


This image (full-frame), 20 second exposure, ISO 2500, shows the Trapezium and nearby nebulosity of M42:


I completed imaging at 2033 MST and slewed the telescope to the star Regulus, the next spectrum imaging target, and began waiting for it to rise higher in the eastern sky. Once it was high enough, I took this 5 second, ISO 100, drift exposure using the Star Analyzer:

Regulus - Spectral Type B7

I closed the observatory at 2102 MST, 52°F.

Comments are welcome; use the Comments section below, or you can Email Me. Thanks.

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