Quote:
Originally Posted by multiweb
Always amazed how you manage to find these things. It's investigative work then you have to figure out where it is when it's not where it's supposed to be and then there's the location on the ground and the timing that come into the mix. I have enough problems finding things that don't move like massive emission nebulae  |
Quote:
Originally Posted by Troy
Interesting as always
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Thanks Marc and Troy, I appreciate your comments.
On the evening of 15th May 2018 (AEST) NEO 2010 WC9 was predicted to glide past the magnificent Globular Cluster Messier 10 (M10) on its way to making its closest approach to our planet.
Estimates of the size of 2010 WC9 range from 197 to 427 feet (60-130 meters). The estimated close approach distance to our home planet is some 0.53 LD, which translates to approx. 126,400 miles (203,400 km).
I decided to use my Canon 7D Mk II to record this event as it has a larger sensor than the ATIK 414EX, and sensor real estate is crucial in locating and recording these fast-moving objects.
After downloading the latest elements in The Sky X Pro, I slewed to the plotted position and began a series of test exposures, but NEO 2010 WC9 was nowhere to be seen. I checked my Latitude & Longitude values and the computer time, as these are crucial settings due to the significant effects of parallax for these close approaches.
Still, the recalcitrant NEO stubbornly refused to make an appearance, so I quickly ran upstairs and checked the desktop PC and it agreed with the notebook located outdoors, at the telescope. So, I decided to keep recording and sure enough, 2010 WC9 entered from stage left (orientation of Canon 7D). I was thrilled to have picked it up, at mag 12.3 to 12.1 as the night progressed. It was some 5 minutes late…
Confident that I could now locate the NEO, I slewed the ‘scope to M10 and began the preparations to record the slowly moving red dot as it approached the globular cluster. It took 11 frames at 60 secs exposure to traverse the field of view, with a 5 second pause between each frame to prevent camera shake caused by the shutter opening.
The “wobbly” appearance of the trail is because of periodic errors in the telescope mount’s gear train, as I was imaging at a relatively long focal length of 1932mm. This appearance is not caused by the asteroid tumbling!
Equipment details:
Tak Mewlon 210 F11.5
Tak x0.8 Reducer
Canon 7D Mk II DSLR
EFL 1932mm
Image details:
UT:
2018-05-15
13:42 – 13:54
Date: 15/05/2018 AEST
23:42 to 23:54 PM AEST
Magnitude: 12.16
RA Rate (arcsecs/sec): 0.153442
Dec Rate (arcsecs/sec): -2.725702
Constellation: Ophiuchus
The FOV of the original frames was approx. 40x27 arcmins, with an image scale of 0.44 arcsec/pixel
60 sec exposures
11 Frames
5 sec pauses between frames.
Processing:
I opened the 11 Frames as Layers in Photoshop CC and performed an “Edit-Align Layers” function to align all the frames. I then set the “Blending Mode” to “Lighten” so the 11 dashes of WC9 magically appeared at the top frame in the Stack.
Back in the 1780’s, as he was compiling his famous Messier Catalogue, I wonder what Charles Messier would have thought about the capability of today’s amateur astronomical equipment and techniques? Over the course of his career, Messier discovered forty nebulae and 13 comets.
I have also attached a higher res shot of the core of M10 where I was able to stack some extra frames. The sinuous trail of the NEO dimmed due to the glare from the GC.
Cheers
Dennis
