NEO 2023 MU2, 5 metre size rock, 0.6 LD (230,00 kms), 2023-06-25.

[Dennis]

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 of the virtual target 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, 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, behind the plotted position, so it appeared to be lagging.
 
Takahashi Mewlon 210 F11.5
QHY268M Camera
Paramount MX+ Mount.
FOV 33x22 arc mins.
Image Scale: 0.32 arcsec/pixel
 
I downloaded the data for NEO 2023 MU2 via SkyTools and plotted the position of the NEO in ST4 Imaging and slewed to the predicted location but did not find the object.
 
As I am required to use my Mount control SW to actually Track on the NEO, it too plotted the object at slightly different coordinates. The mount suggested an RA Rate (arcsecs/sec) of 2.521133 and aDec Rate (arcsecs/sec) of 0.704910.
 
All in all, I was very pleased with this result.
 
SkyTools 4 Imaging data for 23:49pm 25/06/2023 AEST.
2023 MU2
Minor Planet
Apollo class (NEO)
R.A.  19h48m12.8s Dec. -02°52'04" (2000) in Aquila
Magnitude: 16.73
Diameter: 3 - 8 m
Orbital Elements Epoch 2023 Jun 25.
54 observations over 1 oppositions
Apparent Data for 2023 Jun 25  GMT+10 at Back Garden:
Apparent RA:  19h49m27.2s, Apparent Dec: -02°48'36"
Local Sidereal Time:  18h15m

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
 
Cheers
 
Dennis

   

   

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I have just created a composite image, with the Frame of the 120 sec trailed exposure overlaid on a SkyTools 4 Screen Capture, to show the offset. (Red Circle vs ST4 Cross).

What is interesting, is that had ST4 been controlling the mount using the NEO Custom Tracking Rate, NEO 2023 MU2 would have been in the field, albeit towards the edge.

The mount control SW actually had the NEO some way outside the FOV, hence my initial exposure missed it and I had to revert to a 4 panel mosaic search, centred on the the quadrants of the predicted FOV.

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.

Cheers

Dennis

   

[PMSchu]

Hi Dennis,

Again nice work! That difference in position would probably spell doom for a visual observer expecting the NEO to be at the predicted position. The camera is more forgiving.

The MPC added 2023 MU2 to the list of NEOs on 2023 Jun 23, but since it was only going to peak at a predicted 16.8 magnitude, I didn't report it here.   It looks like it was a perfect target object for you.

Phil S.

[Dennis]

Hi Phil

Thanks, no worries about reporting anything as I cannot always get around to setting up, notwithstanding the clouds, etc.

My expectations were set low for NEO 2023 MU2 due to its size and motion so I was astonished to eventually locate it on one of the 120 sec frames.

When I browsed my other frames, I did find a trailed object right at the edges on a couple of them, so I was so pleased that I managed to get at least 1 image tracked faithfully on the NEO towards the centre of the frame.

Cheers

Dennis

[PMSchu]

Hi Dennis,

You are one of the few posters on the forum, so I like to keep you up to date on the NEO situation, especially since you're in the southern hemisphere and so many good objects are visible from down there. It'd be a shame if they were wasted. 

You also take such great images.

Phil S.

[Dennis]

Hey Phil, I just discovered that today (30th June) is Asteroid Day!

https://asteroidday.org/

Asteroid Day is a UN-sanctioned global awareness campaign participated annually on 30 June.

Our mission is to inspire, engage and educate the public about asteroids opportunities and risks.

Every year, we produce Asteroid Day LIVE– a live broadcast with asteroid content and commentary from astronauts, experts and celebrities. Asteroid Day events are held around the globe thanks to thousands of independent Asteroid Day Event Organizers.

Cheers

Dennis

[bigmasterdrago]

Dennis, Amazing work. In your composite, it appears to be located at 19h 49m 15s, -2° 47' 56". Is that the position at the beginning of exposure (11:48:39UT)?

And are you near the center of Brisbane?

Reason I was asking is you seem to be a lucky guy to have caught it 25 arc minutes out of position. Horizons, SkyTools and several other apps do not agree with you position.

[Dennis]

Dennis, Amazing work. In your composite, it appears to be located at 19h 49m 15s, -2° 47' 56". Is that the position at the beginning of exposure (11:48:39UT)?

And are you near the center of Brisbane?

Reason I was asking is you seem to be a lucky guy to have caught it 25 arc minutes out of position. Horizons, SkyTools and several other apps do not agree with you position.

Hi BMD

Thanks for following up, it is good to have an independent review of these marginal objects.

When the NEO did not appear where it "should" have been, I began to sweep around the region and the 4th 120 sec exposure produced this stationary object, with the Mount set to Track on the NEO, so I assumed I had located it. I was a little surprised that both SkyTools and the Mount Control SW had positioned the OTA in the "wrong" position, as both had been quite accurate on previous objects.

I have attached the File Header from CCDStack which provides some detailed information about the 120 sec Frame.

The File Header provides the site Lat Long and writes that the exposure time was the time at the beginning of the 120 second exposure.

Hope that helps, let me know what your investigation uncovers.

Cheers

Dennis

   

   

[Dennis]

I used the JPL Horizons system to plot the position of 2023 MU2 and have marked this on the ST4 Camera View.

The ST4 Camera View shows a red cross for the ST4 plotted position. The manually drawn yellow circle shows the JPL Horizons plotted position.

I used the FITS Header information from Frame 157 in my series of images and it pretty much lands right on the JPL Horizons plotted location, so I am now confident that I did record 2023 MU2.

ST4 plotted the position more accurately than my Mount Control software that is used to set the custom track rate, to track on the NEO.

So, had I used the ST4 pointing solution, NEO 2023 MU2 would have been in the FOV of my camera, whereas using the mount control software to point the scope placed the real 2023 MU2 outside of the FOV  of the camera.

Well done ST4.

Cheers

Dennis