NEO 2023 MU2, 5 metre size rock, 0.6 LD (230,00 kms), 2023-06-25.
Here we have a 120 sec exposure image of the NEO 2023 MU2 with the telescope tracking on the rapidly moving NEO. I could easily see the orbital movement in real time on the computer screen.
Whilst the good folks and visitors of the City of Brisbane were safely sleeping, I was keeping an eye on this 5 metre sized cosmic rock as it sailed by our back garden on Sunday 25th June 2023, at a closest approach of some 230,000 kms, well within the orbit of our Moon.
My first 120 sec exposure did not locate the NEO so I had to slew the telescope to each corner of the FOV and take a series of 120 sec exposures in the hope of locating the rapidly moving mag 16.8 object. One of these frames revealed the location of NEO 2023 MU2, some 25 arc mins off, that is behind the plotted position, so it was lagging.
Equipment
Takahashi Mewlon 210 F11.5
QHY268M Camera
Paramount MX+ Mount.
FOV 33x22 arc mins.
Image Scale: 0.32 arcsec/pixel
TSX Report for Centre of Chart with image of NEO 2023 MU2
RA (Topocentric): 19h 50m 39.845s
Dec (Topocentric): -02° 45' 24.14"
RA (2000.0): 19h 49m 25.589s
Dec (2000.0): -02° 48' 55.41"
TSX Report for plotted position of NEO 2023 MU2
RA (Topocentric): 19h 51m 54.0s
Dec (Topocentric): -02° 42' 39"
RA (2000.0): 19h 50m 39.8s
Dec (2000.0): -02° 46' 11"
Object Name: 2023 MU2
RA Rate (arcsecs/sec): 2.524225
Dec Rate (arcsecs/sec): 0.706238
Date/Time AEST: 25/06/2023 1:48:39 PM at exposure start
Date/Time UTC: 25/06/2023 11:48:39.060 at exposure start
I have included a Screen Capture of The Sky X Pro showing the plotted position, overlaid with the image showing the actual position.
That’s awesome, Dennis. I always look forward to your interesting projects and write-ups. Quasars the other week, NEOs this week.
Asteroid heading for Earth? Who needs Bruce Willis, a spaceship and a thermonuclear device? Just give Dennis a big-arsed laser and he’ll sort it out from his suburban back garden in Brisbane (while we sleep).
Thanks, Steve, Derek, and Andrew, I appreciate your comments.
I was making use of The Sky X Pro and SkyTools 4 Imaging (ST4) for this project and had to perform a lot of mental gymnastics as to field orientation, and then the FITs files were rotated by 180 degrees, so it was quite challenging to establish the correct FOV and orientation at times at the scope, with even differing star ID's thrown into the mix.
With such close approach objects moving at a reasonable rate, the effects of Parallax and slight inaccuracies of parameters such a time, Lat, Long, etc. can magnify any offset.
Here is a file with the trailed imaged overlayed on an ST4 screen print, showing the actual vs predicted positions.
That’s fantastic Dennis. Your ability to track down and capture these targets is seriously impressive!!
Thanks Dave, I appreciate your comments.
I have since gone back and blinked through several images which I randomly captured (in panic mode) trying to locate NEO 2023 MU2, after it did not initially appear in its predicted position.
On some of them, as I just nudged the mount randomly, I have found candidates right at the edge of the frame. It wasn’t until I methodically searched around the predicted location that I found the NEO towards the centre of the frame.
I understand that for some of these NEO’s, their predicted orbits are calculated as if only the Asteroid and the Sun exist, so when they get closer to the Earth then they are perturbed by our planet, and this may make the prediction less precise.
From quasars to 5m rocks... Is there anything you can't find?
I'm very impressed with this, Dennis. Congrats on finding something so small, faint and speedy...
Cheers,
V
Thank you, Steve, I appreciate your kind words.
I enjoy these smaller targets as I suck as imaging DSO’s.
I use The Sky X Pro to download the orbital elements of the NEO and then <Click> on the object in TSX to set the custom tracking rates for the NEO’s then the MX+ Mount faithfully tracks the Asteroid, leaving the stars to trail.
Wow, 5m is very small. That is a very impressive capture Dennis!!
Thank you, Clare and Peter, I appreciate your comments.
If I were to track/guide at the Sidereal Rate, the photons from the NEO would be spread so thinly across its trail that they would not register using my set up, I would need a much larger aperture or more sensitive camera.
By Tracking on the NEO, the photons all get to fall consistently on the same few pixels, so I get to record it.
Horizons outputs a very accurate topocentric ephemeris based on your observing location/altitude, essential for NEO's.
Great job
Joe
Thanks Joe, I used The Sky X Pro to download the elements just before the session, so they were "fresh" and then I did the same using SkyTools 4 Imaging. Both had me pointing a few arcmins away from the actual object I located.
I suppose that I could have imaged the "wrong" NEO, but I thought what are the chances of a similarly fast-moving mag 16’ish object being in the same region, so I assumed it probably was NEO 2023 MU2.
Is it possible to use Horizons to go back to the date/time of my images, to generate the predicted RA/DEC positions to compare them to TSX and ST4?
Dennis,
Yes, easily, you just have to set the date range for the time you want.
Joe
Thanks for that Joe, I did as you suggested and then plotted the JPL Horizons plotted position overlaid on The Sky X Pro and SkyTools 4 Imaging plotted positions.
My capture of NEO 2023 MU2 coincided with the JPL plot, so I am now confident that I did record the correct object.
If I had used ST4 to point my telescope, I would have located NEO 2023 MU2 in the camera FOV whereas the plotted position in TSX64 placed it just outside of the FOV, although I had to use TSX to track at the custom rate of the Asteroid.
An enjoyable investigation over my morning cup of tea.
5m?!... far out Dennis. Freakin amazing. 
