Close Approach of 2025 SW

[PMSchu]

CNEOS predicts that the newly discovered NEO, 2025 SW, will make a close approach on 2025-Sep-25 15:56±<00:01 UT at a distance of 0.01069 AU moving with V Relative=8.08 km/sec, H=22.8 magnitude, diameter 73 m - 160 m and 'Rarity'=2. As of September 21, there was a 4 day observation arc, the Condition Code=7 and the Earth MOID=0.0080382 AU. The solution date was 2025-Sep-21 06:51:31 PDT. The initial reported observation was by ATLAS Chile, Rio Hurtado on 2025-09-17. This NEO isn't quite large enough to make the MPC's list of Potentially Hazardous Asteroids (PHAs). CNEOS hasn't calculated any future close approaches as of today.

Using MPC's orbital elements for the epoch 2025 Sep 22 0000 UT, ST 4.1.11.18 Visual Pro predicts that 2025 SW will reach a peak brightness of 14.0 on 2025 Sep 25 at 2000 EDT (Sep 26 0000 UT) with 2025 SW traveling through Pegasus at ~60"/minute, but in twilight as seen from Columbus, Ohio. It will dim slightly and rise higher above the horizon as the sky darkens, offering a better view. Close approach is predicted (to the nearest hour) on 2025 Sep 25 at 1200 EDT (1600 UT) when 2025 SW will be 14.1 magnitude still traveling through Pegasus at 64"/minute, but in daylight and below the horizon in Columbus. This NEO is predicted to be brighter than 16 magnitude from September 22 (in Capricornus) to September 28 (in Andromeda).

Here's the Object Info dialog for 2025 SW:    

Observers should follow the directions for downloading orbital elements described in the 'Important Thread' at the top of this forum section to obtain the most accurate elements for their ephemeris predictions.

Good hunting,

Phil S.

[Dennis]

Thanks for the heads up, Phil.

This is how it looked from Brisbane on the evening of 23rd Sept 2025 (20:36 – 21:06 AEST) (UTC+10).

UT2025-09-21T10:36 to 11:16

I grabbed 30x60 sec exposures tracking on the NEO.

Celestron C11 at F10 (2800mm) ASI2600MM Pro.

Dennis.

   

[Dennis]

I have just set up again - 2 nights of clear skies on the run - yay!

This is a single, unprocessed 60 sec exposure of 2025 SW tracked on the NEO, cropped to 1920x1200 at full res, from a few minutes ago (7:52 PM AEST). (9:52 UT).

Dennis.

   

[PMSchu]

Hi Dennis,

Both of your images look really nice. The tracking of your mount is excellent.

Thanks.

We just had 2025 SU4 rip past us this morning in Columba at 51"/second at 0.06 LD! There wasn't any warning for it unfortunately as it was discovered only yesterday.

Phil S.