Close Approach of 2023 GG

[PMSchu]

CNEOS predicts that the newly discovered NEO 2023 GG will make a close approach on 2023-Apr-11 00:25±<00:01 UT at a distance of 0.01018 AU moving at 10.59 km/sec. H=23.3 magnitude, the diameter is 59 m - 130 m, 'Rarity'=1, Condition Code=7, 3 day observation arc. The Earth MOID=0.00395153 AU. This NEO was first observed at ATLAS South Africa, Sutherland on 2023-04-05.

Using MPC's elements for 2023 Apr 8 0000 UT, ST4v predicts that this NEO will reach a peak brightness of 15.6 magnitude on 2023 Apr 9 at 2200 EDT when it will be moving through Hydra at 66"/min. The predicted close approach time (to the nearest hour) is 2023 Apr 10 at 2000 EDT at 15.7 magnitude moving through Cancer at 87"/min in daylight from Columbus, Ohio.

Here's the Object Info dialog for this close approach:     

Good hunting,

Phil S.

[Dennis]

Hi Phil

I was outdoors running a disturbed system test as I took the imaging train apart to purge the sensor chamber with Argon gas after the frosting experience. I also took this opportunity to tidy up and re-route some cables and re-orient the camera. When I called into the kitchen for my cup of tea and Easter hot cross bun, I saw your message.

What a great opportunity to test out the re-configured rig. I am pleased to say it all worked, the NEO was exactly where ST4 plotted it from a fresh download from the MPC.

This series was taken when 2023 GG had crossed the Meridian, I hope I’ve got the E-N arrows correct!

Local Time:
Sunday 9th April 2023.
Start: 8:29 PM (AEST UT+10)
End: 8:34 PM (AEST UT+10)
10 frames

UTC Time:
UTC: 09/04/2023 10:29 to 10:34

FITs Header for Frame 006
NEO 2023 GG_2x2_30secs_006.fit
UTC  9/04/2023 10:30:44
Exposure      30
Temperature  -10
Pixel_size_X  7.52
Pixel_size_Y  7.52
Binning X    2
Binning Y    2
SITELAT      '-27 31 28.00'      / SBIGFITSEXT Latitude of the imaging location 
SITELONG      '-153 03 40.00'      / SBIGFITSEXT Longitude of the imaging location 
LST          '+09 52 38.62'      / Local sidereal time                           
OBJCTRA      '09 29 01.185'      / SBIGFITSEXT The right ascension of the center o
OBJCTDEC      '-15 16 18.67'      / SBIGFITSEXT The declination of the center of th
OBJECT        '2023 GG '          / SBIGFITSEXT The name of the object imaged     
LOCALTIM      '9/04/2023 08:30:44.659 PM STD' / Local time at exposure start       

Cheers

Dennis

   

[PMSchu]

Hi Dennis,

It looks like the imaging system is working great! Tracking is spot on, too. Excellent work.

I'm glad that you're getting some decent weather. I hope it keeps up.

Phil S.

[Dennis]

Hi Dennis,

It looks like the imaging system is working great! Tracking is spot on, too. Excellent work.

I'm glad that you're getting some decent weather. I hope it keeps up.

Phil S.

Thanks Phil, a couple of nights ago we had a major thunderstorm and it is the first time in my 30 years in Australia that I felt our house shake and rattle as the thunder claps burst overhead and the back garden filled up with water from the downpour.

A couple of days later, the strong Westerly winds kicked in, making the skies clear and transparent, if a little unsteady in terms of seeing.

One problem I am having is that the mount is tracking so well and I am not auto guiding, so I cannot "dither" my exposures to remove the fixed pattern noise of the CMOS sensor, hence the blotchy background.

Cheers

Dennis

[PMSchu]

That sounds like quite a powerful storm! Glad you're safe.

Can you use autoguiding anyway? Does it really matter for astrometry of minor planets? The tracking is really excellent. 

There are some more large NEOs coming. I missed (4486) Mithra that's currently 16.1 magnitude in Perseus 0.2 AU distant. It was brighter several weeks ago. The estimated size is 1-4 km.

According to CNEOS (4486) Mithra's close approach occurs 2023-Apr-11 16:49±< 00:01 UT at a distance of 0.16267 AU at V Relative=13.45 km/sec, H=15.6 magnitude, diameter 1.849±0.022 km, 'Rarity'=2, Condition Code=0, Earth MOID=0.0462852 AU. 

Phil S.