Asteroid 324 Bamberga at opposition in September 2013.

Being one of the largest known asteroids, with a diameter of about 230 km, its magnitude however varies greatly due to a very high orbital eccentricity.
It is brightest on September 13 2013, at magnitude +8.1, after which it fades again beyond visibility in amateur telescopes. It takes 22 years before it reappears at this magnitude.
It makes a close approach of about 0.78 AU at perihelion, no other asteroid so large gets so close.

The asteroid was discovered in 1892 and is named after the German city of Bamberg.

The animated GIF which is available below shows the movement in the sky of this asteroid during the period of just 2 days (Sep. 03 and Sep 04, 2013).

Previous/older images:

Image data

Object info
Name 324 Bamberga
Type Asteroid
Discovered 1892
Diameter 230 km
Minor planet category Main belt
Aphelion 3.59 AU
Perihelion 1.77 AU
Orbital period 4.39 y
Rotation period 29.4h
Spectral type C-type asteroid
Abs. magnitude 6.82
Image info
Image date Sep. 03 & 04, 2013
Light frames 5x 3 min x 2. Ha unbinned
Total integration 2x 15m
Dark frames 5x
Flat frames 20x p. filter unbinned, created with an A3 size Posterpoweruk flatfield panel
Bias frames
Software used CCDOps, CCDSoft, ImagesPlus, Photoshop CS4
Processing CCDOPS was used for focussing. Image Acquisition was done using CCDSoft.
All separate frames were calibrated, aligned and stacked in ImagesPlus 2.8.
Photoshop CS4 was used for further processing – curves adjustment, levels adjustment, etc.
Equipment info
Telescope TMB/LOMO 80/480
Corrector Televue 2″ TRF 2008 flattener/reducer (FL: 384mm f/4.8)
Mount Losmandy G-11 Gemini
Camera SBIG ST-8300M
Guide camera Atik 1HS Mono
Guide scope Vixen VMC110L
Autoguide software PHD Guiding
Filters Baader 2″ 7nm Ha + IDAS LPS-P2
Location Landgraaf, The Netherlands
Image comments

Not one of the best images due to noise issues, but it clearly shows the movement of the asteroid during these 2 days.