Asteroid 433 EROS light curve

[lukebl]

Hi folks,

I had a go at capturing Asteroid 433 Eros early this morning. Eros is a fascinating object, discovered in 1898 and one of the largest Near Earth Asteroids. It's got a highly irregular shape and orbit, and was used in 1900 to make parallax measurements to determine the Astronomical Unit.

It first came to my notice back in my youth in 1975 when it did a close earth flyby, which was reported in Sky and Telescope, to which I was a subscriber. Back then it reached 7th magnitude, and its brightness varied by a whole two magnitudes during its rotation of 5.270 hours. The NEAR Shoemaker probe visited Eros twice, first with a 1998 flyby, and then by orbiting it in 2000 when it extensively photographed its surface. On February 12, 2001, at the end of its mission, it landed on the asteroid's surface using its maneuvering jets.

Right now it's about mag 12.3, and I took a series of 30 second exposures to capture its motion and take some astrometric measurements. The magnitude measurements show a nice even curve with an amplitude of about 0.15 magnitudes over a period of about two hours. Images were captured with a 250mm f/4.7 Newtonian and an Atik428ex,  0.858 arcsec/pixel. Field of view 27.6 x 20.8 arcmin.

Animation:

Position every 5 minutes

Light curve:

 

 

 

 

[Scooot]

Thanks for the write up, it makes the image even more fascinating.