The Occultation of a W=13.0 Star for 0.5s by Asteroid 1998 BA9

Sun eve Jan 18, 2026 at 10:15:58pm

OWc page

 

This is a faint asteroid with a disappearance of only 0.5s. A difficult event, but if conditions are good, may be do-able. Requires a drive north, although Karl's just inside the southern limit at home

 

Alt=59 in Gemini, not far from Assisi

 

     

Kirk Bender

I got a 0.2669s event for 1998 BA9, 8x, near Ano Nuevo state park on hwy 1. This was much shorter than the max predicted, 1.06sec, and I was only 20m from the centerline.
The prediction must have been inaccurate for the duration and/or path. The target was noisy but I got an event just a second before predicted time and with an NIE sigma distance of 20.4.

magDrop report: percentDrop: 100.0  (magDrop cannot be calculated because A is negative)

DNR: 2.89

D time: [06:15:57.5952]
D: 0.6800 containment intervals:  {+/- 0.0204} seconds
D: 0.9500 containment intervals:  {+/- 0.0543} seconds
D: 0.9973 containment intervals:  {+/- 0.1050} seconds

R time: [06:15:57.8621]
R: 0.6800 containment intervals:  {+/- 0.0204} seconds
R: 0.9500 containment intervals:  {+/- 0.0543} seconds
R: 0.9973 containment intervals:  {+/- 0.1050} seconds

Duration (R - D): 0.2669 seconds
Duration: 0.6800 containment intervals:  {+/- 0.0303} seconds
Duration: 0.9500 containment intervals:  {+/- 0.0690} seconds
Duration: 0.9973 containment intervals:  {+/- 0.1175} seconds