Close Approach of 2023 FH7

[PMSchu]

CNEOS predicts that the newly discovered NEO 2023 FH7 will make a close approach on 2023-Mar-30 18:08± 00:02 UT at a distance of 0.00111 AU traveling at 8.69 km/sec. H=28.7 magnitude, estimated diameter is 4.7 m - 11 m, 'Rarity'=0, Condition Code=7, with a 1 day observation arc. The Earth MOID is 0.00104039 AU. This object was first observed at Mt. Lemmon Survey on 2023-03-28.

Using MPC's elements for 2023 Mar 29 0000 UT, ST4v predicts that this object will reach a peak brightness of 16.7 magnitude on  March 30 at 1300  EDT at 174.6k km distance moving through Volans at 582"/min in daylight and below the horizon in Columbus Ohio. The close approach (to the nearest hour) is predicted to occur on 2023 March 30 1400 EDT 170.5k km distant at 16.8 magnitude, still in Volans moving at 10.3 "/sec in daylight and below the horizon in Columbus, Ohio.

This is a southern hemisphere screamer with very little warning. I hope Dennis's mount can track that fast  .

Here's the ST4v Object Info dialog for this NEO:     

Good hunting,

Phil S.

[Dennis]

Hi Phil

Rain, thunderstorms and sheet lightening kept me indoors last night, so unfortunately I missed this one. We are certainly having some weird weather....

Cheers

Dennis

[PMSchu]

Yes, you certainly appear to have angered the sky gods. Did you purchase some new astro equipment recently? Maybe Bobbo caused it  ?

This one was a real screamer, sorry you missed it. I hope they're getting the reservoirs full.

Phil S.

[Dennis]

Well, what a night of inglorious failure!
 
After last night’s thunderstorm, the Brisbane skies cleared and as a bonus, the rain had cleansed the atmosphere of all the heat haze. A clear night was forecast (Thursday 30/03/2023 AEST) so I set up for 2023 FH7.
 
My MX+ mount can track at the (custom) rate of a selected object (as distinct from Sidereal Rate) but I have to use the mount SW to do this, which means I also have to use it for finding/tracking the objects.
 
Anyhow, I slewed to the plotted position of 2023 FH7 and began a series of exposures.
 
Unfortunately, something went wrong, as when I inspect the images this morning, 2023 FH7 is consistently some 2 or 3 FOV’s ahead (approx. 1 to 1.5 degrees) of where I grabbed the images.
 
Here is one 60 sec sub-frame tracked on the "phantom" position of 2023 FH7 showing that I missed it by “just that much”! I suspect that if I had been in the right FOV, my system might well have recorded the faint spec of the fast moving NEO.
 
Cheers
 
Dennis

   

[PMSchu]

That has to be really frustrating! With all the bad weather you've had for months, too. Which orbital elements did you use to calculate the positions?

That's a large error; however the observation arc was only 1 day & the Condition Code or Uncertainty was 7 at the time that I posted the notice here. Is there a way to add an offset to the positions to acquire exposures around the predicted position? That adds a lot of extra work, unfortunately.

I think that your system is sensitive enough to detect a 16.7 magnitude NEO on a 60 sec exposure, if it's tracking it accurately. This is based on past images that you've posted.

Phil S.

[Dennis]

Hi Phil

Thanks for your comments, I appreciate them.

I used the built-in download procedure of the mount’s control SW, so I will have to inspect my Laptop PC and various HW/SW settings to see if I have inadvertently introduced an operator error along the way.

I was also distracted by guests who dropped by for the evening, so my full attention wasn’t on the rig chugging away in the back garden.

A JPL Horizons download and the ST4 prediction (using Astorb.dat) would both have put me in the right spot.

For long focal length (2170mm) unguided imaging I have to use the mount SW for its built-in modelling, but I am going to experiment with pointing at an ST4 acquired target, but then see if I can invoke the custom tracking rate within the mount SW even, though ST4 provides the Target selection and acquisition functions.

Always something to learn with this hobby, I wonder what Clyde Tombaugh would think today, given the amazing HW and SW capabilities in the hands of us amateurs.

Cheers

Dennis

[PMSchu]

Clyde would love our detectors with no reciprocity failure & the ability to stack images. What could those old timers have achieved with this new technology!

Phil S.

[bigmasterdrago]

If the big observatories can find it, so should we.
https://minorplanetcenter.net/db_search/...d=2023+FH7

Use the Horizons osculating elements for the time/date you expect to image it. SkyTools makes it possible to track these fast movers.

[Dennis]

I checked the settings on my Laptop that I used in my attempt to record 2023 FH7 and they all looked okay. In the test images I took (tracking at the Sidereal Rate) at the set up stage, they were correctly centred on the plotted position of 2023 FH7, but the rock was moving too fast for the 30 sec exposure to register its trail. I tried 2x2 Bin and 4x4 Bin modes ( I know that this does not increase the photon flux) to see if something might show up.

Its when I used the Mount SW to Track at the Custom Rate of 2023 FH7 that I ran in the offset problems and I guess I have to put that down to operator error, as all the settings post that session seem to be in order.

I guess I'll have to wait for the next one.

Cheers

Dennis

   

[PMSchu]

2023 FM is predicted to be ~2 magnitudes brighter, but the moon intereres. 

Phil S.