Close Approach of (152637) 1997 NC1

[PMSchu]

The kilometer-sized Aten class NEA, (152637) 1997 NC1 is predicted to make a close approach on 2026 Jun 27. Maximum brightness is predicted to be 10.1 magnitude. I'll provide an update closer to the time of the event.

Phil S.

[PMSchu]

Here's the update for the close approach of (152637) 1997 NC1.

CNEOS predicts that the kilometer-sized, Aten class NEA, (152637) 1997 NC1 will make a close approach on 2026-Jun-27 11:16±<00:01 UT at a distance of 0.01715 AU, moving with V Relative=8.89 km/sec, H=17.9 magnitude, diameter 710 m - 1.6 km and 'Rarity'=3. As of 2023 September 1, there was a 9202 day observation arc, the Condition Code=0 and the Earth MOID=0.015271 AU. The solution date was 2023-Sep-01 05:59:21 PDT. This NEA was discovered 1997-07-05 by NEAT at Haleakala. This approach is close to the MOID. A slightly closer approach at 0.01699 AU is predicted on 2133 June 28. This object is on the MPC's list of Potentially Hazardous Asteroids (PHAs) that you can download using SkyTools.

Using MPC's orbital elements for 2026 Apr 30 0000 UT, ST4.1.11.20 predicts that (152637) 1997 NC1 will  reach a peak brightness of 10.1 magnitude on June 28 0000 EDT at a distance of 0.018 AU traveling through Serpens Cauda at 41.9"/minute. Close approach (to the nearest hour) is predicted on June 27 0700 EDT at a distance of 0.017 AU traveling through Ophiuchus at 10.2 magnitude and 42.6"/minute, but in daylight and below the horizon in Columbus, Ohio. This NEA should be brighter than 16 magnitude from June 10 (in Cepheus) to July 21 (in Crux), but it will be too far south to be observed at 40°N after June 30.

Here's the Object Info Dialog for (152637) 1997 NC1:    

Since this is a "Rarity'=3 event, here's the predicted path of this object as seen from Columbus, Ohio:    

It looks like there will be some moon interference around the time of close approach, but this NEA should be bright enough that it won't be a problem.

Good hunting,

Phil S.

[Dobsonian Power]

There we go with 1997 NC1 last night

[Dobsonian Power]

1997 NC1

[Dobsonian Power]

Just captured



Goldstone radar will watch it. 

"1997 NC1 was discovered by NEAT (566) at Haleakala, Hawaii on 1997 July 5.
The absolute magnitude of 17.9 suggests a diameter within a factor of two
of 900 meters.  The diameter, optical albedo, and spectral class have been measured but
give conflicting results.  The rotation period, lightcurve amplitude, and pole
direction are unknown.  This object has not been observed with radar previously."

"1997 NC1 will approach within 0.017 au (6.8 lunar distances) on 2026 June 27.
We will use the 34 m DSS-26 antennas as a transmitter (7190 MHz)
and the 34 meter DSS-13 antenna as a receiver.  Observing time is scheduled on June 24, 25, and 27.
This observing configuration should yield CW detections
on each day and may provide SNRs strong enough for coarse resolution imaging if the
rotation period is slow."

[PMSchu]

That's a very nice image sequence. (152637) 1997 NC1 is approaching quickly. SkyTools 4.1.11.21 Visual Pro predicts that it will be 13.9 magnitude tonight in Cygnus. How is the predicted brightness comparing with your observations?

CNEOS has recomputed the orbital elements. There's now a 10574 day observation arc, the Condition Code=0 and the Earth MOID=0.0167127 AU. The solution date was 2026-Jun-18 05:47:52 PDT. This pass is within 0.00044 AU of the minimum distance. It will be slightly closer on 2133 Jun 28 at 0.01699 AU.

(523808) 2007 ML24 makes a close approach on 2026 July 4. That's only a Rarity=2 event predicted to reach a peak brightness of 16.0 magnitude.

Phil S.