Image Links | |
Published image | Full resolution |
Target Information | |
Main Target Designation(s) | Neptune |
All Exposures | |
Date(s) of acquisition | 2018Aug02 at 07:29UT |
Location | Defiance, MO |
Capture resolution | 352x340 |
Target Altitude | 27.0° |
Red Exposures | |
Total capture | 1002 x 563ms of 566" video at 75% gain |
Stack source | 20% of 566" video at 1.8 fps (avg) |
Green Exposures | |
Total capture | 1014 x 450ms at 75% gain |
Stack source | 20% of 458" video at 2.2 fps (avg) |
Blue Exposures | |
Total capture | 1033 x 350ms at 75% gain |
Stack source | 20% of 361" video at 2.8 fps (avg) |
Equipment | |
Imager | ZWO ASI174MM |
Filters | ZWO 1.25" RGB |
Telescope/Lens | Celestron C14 XLT SCT |
Magnifiers | Tele Vue 2x Powermate |
Effective Focal Length | 7820mm (f/22) |
Mount | Celestron CGE Pro |
Focuser | Moonlite 2.5" CSL |
Software | |
Acquisition | FireCapture 2.5 |
Guiding | None |
Processing | AutoStakkert 3, PixInsight 1.8, Photoshop CC |
Neptune: 4,355,464,393 km (2,706,360,103 mi) away from us on August 2, 2018, the morning on which I attempted to image it. Could it possibly turn out to look like anything but a star through my planetary rig? The answer: yes!
As the saying goes, "it's not much, but it's mine!" Coming in at a paltry 2.3 arcseconds, it's only about 13% the size of Saturn in our sky right now, and at a visual magnitude of 7.8 (and unlike Saturn), you have no chance of seeing it with your naked eye.  With my imaging rig used here, the disc (in perfect focus and conditions) would span only 15 pixels.  There's not anything that makes photographing this planet easy, nor should one ever expect (under reasonable circumstances) to get any sort of detail. So, the fact that I got a spheroid-looking object is a total success in my book!
As far as tough-to-photograph planets go (Neptune, Uranus, Mercury), Neptune may be the neatest. Not only is it staggeringly far away, the blue color caused by the red/green light absorption by the Methane composition in the clouds is simply beautiful -- even on the tiny sphere I captured! I'm glad to add this one to my growing solar system image collection. Now I just need good images of Mercury, Venus, and Uranus to complete it!