On December 26th we were invited to christmas dinner at my sisters place. I brought the Vixen Polarie, the Takahashi FS-60CB and the Nikon D750 to do some astrophotgraphy during the evening.
The image above records some faint nebulosity across central Orion. From the horsehead nebula B33 silhouetted against IC434 to the flame nebula NGC 2024. In the upper left, the M78 nebula with its surrounding NGC objects is also visible. In the corner a hint of Barnards loops is discernible
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Barnard 33 is the horse-head shaped dark cloud silhouetted agains the glow of excited hydrogen which goes by the name of IC434. To the left is the Flame Nebula NGC2024, which is an odd nebula, because it is orange, and apparently a mixture between reflection and emission nebula.
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On sundey 16th Decmber 2018 – the comet had its closest approach to Earth, it was only 11.7 million kilometers away, the 10th nearest comet in history. Nikon D750 with 70-200mm lens at 200mm f/4, 39x30s, Vixen Polarie.
Read MoreToday I used a break in the clouds to test how the astro-modified Nikon D7000 works with a h-alpha Filter. As the weather was very unstable, I didn’t set up the laptop for guiding, so some images were unusable due to trailing and passing clouds and full cloud cover at the end of the exposure resulted in oly 83x30s unguided exposures. Which way too short, but I am happy with the result under these circumstances.
NGC1499, Baader Planetarium, 1,25″ h-alpha Filter, 83x30s (41,5m) exposure, Astro-Professional 80mm f/7 refractor.
In the first night I used my 80mm f/7 ED Apo for unguided 30s sub-exposures, in the second night, the 127mm f/8 Apo with 120s guided exposures…
M31, The Andromeda Galaxy, 199x30s, Nikon D750, Astro-Professinal 80mm f/7 refractor, processed in Regim, Fitswork, Photoshop and Lightroom
I was actually heading to bed when I noticed, that the sky cleared up enough to try to photograph Comet 64P/Swift-Gehrels.
As I wanted to create an image that included the Andromeda Galaxy, I used the 70-200 zoom and set it at about 130mm.
Comet 64P/Swift-Gehrels, 33x30s exposures, AF-Nikkor 70-200 f/4, at 130mm, ISO 2500, Nikon D750, Vixen Polarie.
On November 5th I had the opportunity to do another test, this time using the 300mm lens, I also used the California Nebula as the target.
NGC1499, the California Nebula, 192x30s (1h 21min), Nikon D7000a, AF-S NIKKOR 300 mm 1:4E PF ED VR, calibrated in Regim, processed in Fitswork, Photoshop and Lightroom. Mount: Vixen Polarie.
The California nebula is hydrogen gas which is irradiated by the intense UV radiaton from Xi Persei, the bright star near the center of the image. It is about 1250 light years distant and is one of the intrinsically brightest and hottest stars visible to the unaided eye. It weighs in at about 40 solar masses. The surface temperature is a whopping 35000 Kelvin.
After I bought the D750 I rarely used the D7000 any more. As it has been heavily used it would probably not get a lot if I sold it, so It mostly stayed in the closet.
Then I learned that the Nikon D7000 sensor is still used in current astronomical CMOS cameras (e.g. ASI071MC Pro or QHY168C) apart from the cooled sensor the main advantage of the astronomical cameras is the better response to H-alpha emission because of different IR-cutoff wavelength.
H-alpha emission is the red light created when young, hot stars excite hydrogen gas in the interstellar medium. Regions of onging star birth are usually distinctly red. Sadly regular DSLR cameras pick up that red light only very faintly.
After a discussion with a colleague of the Vorarlberger Amateur Astronomen I plucked up the courage to take the camera apart and get rid of the IR blocking filter. Read More
NGC 891 is a beautiful spiral galaxy which is seen perpendicular to it’s rotational axis, so we see it edge on.
It is located in Andromeda, so there are many foreground stars.
I have seen it in telescopes as small as 15cm aperture, in my 250mm the dust lane becomes visible, but in a larger scope, like the 40cm I recently observed with, it is a really beautiful sight. But of course not as detailed as in this image.
NGC 891, Galaxy in Andromeda, distance: ~30 million light-years- 45*180s (2h 15min), QHY163c, Astro-Physics 127mm f/8 refractor.
The Vorarlberger Amateur Astronomen acquired a QHY163c cooled CMOS camera. It is based on a Panasonic Micro-Four-Thirds (m43) sensor, but has added cooling and an astronomical suitable ir-cut filter. Read More