All images have been acquired using the 1000mm diameter (T1M) telescope at Pic du Midi (see here for more informations). The detector is a CHUNGARA CCD camera embedding an E2V 47-10 CCD (backside illuminated 1024x1024 CCD, 13µm square pixels) cooled at -30°C. All image processing have been achieved by PRISM.
The Chungara CCD camera mounted at the T1M Nasmyth focus, a focal reducer has
been employed to reduce focal length from 16m to 5.6m. This focal reducer is
not optimized for such a large CCD (13x13mm). The Chungara camera is the cylinder
below the black fan.
The next table summarizes the magnitude that has been reached, using different filters at a focal length of 5600 mm
Filter |
Exposure time (s) |
Magnitude reached (SNR=3) |
B |
30 |
~ 19.7 |
R |
30 |
~ 20.7 |
| DH |
120 |
~ 21.4 |
DH |
300 |
~ 22.2 |
DH |
3600 |
~ 23.2 (note Elevation=25°) |
DH filter, is a filter that passes light from 550 nm to 930 nm. It is very convenient to use it, because it removes all the OH sky background lines above 950 nm that are responsible for fringing when using back side illuminated CCDs.
M57 (Ring Nebula) : R=250s V=180s B=330, 1.5" seeing,
Focal length = 5600 mm 0.48" per pixel. Digital Developpement Processing
M57 (Ring Nebula) : 250 sec exposure, R filter, 1.5"
seeing, Focal length = 5600 mm 0.48" per pixel. High contrast view.
N7009 (Saturn Nebula) : R=405s V=165s B=100 exposure, 1.5"
seeing, Focal length = 5600 mm 0.24" per pixel (Oversampled by software).
M33 Red=I Green=R+V Blue=B : I=720s R=360s V=840s B=720 exposure,
1.5" seeing, Focal length = 5600 mm 0.48"/pixel 6x6 Arcmin Field.
Digital Developpement Processing
M33 Red=R Green=V Blue=B : R=360s V=840s B=720 exposure, 1.5"
seeing, Focal length = 5600 mm 0.48"/pixel 6x6 Arcmin Field. Digital Developpement
Processing
50000 Quaoar, the largest Kuiper Belt Object Known : 2880 (basic
120s) sec exposure, 1.6" seeing, Focal length = 5600 mm 0.48"/pixel
4x4 Arcmin Field. Over 2880 sec the object is slightly elongated. Single 120sec
exposure shows a star like object.
76803 Kuiper Belt Object: 3720 (basic 300s) sec exposure DH
Filter, 1.4" seeing, Focal length = 5600 mm 0.48"/pixel 3x3 Arcmin
Field. All the basic 300s exposure have been shifted to compensate the very
slow asteroid motion.
Hereafter are the measurments :
76803 C2004 07 15.99641 21 02 37.10 -20 00 17.9 22.10R 586
29P/Schwassmann-Wachmann 16/07/2004 - 01h43m34s 1300sec exposure
0.48"/pixel 3x3 Arcmin Field. All the basic 60s exposure have been shifted
to compensate the comet motion.
Venus 17/07/2004 - 04h27m41s 11sec exposure (combined from
0.300sec exposure), 380nm Filter 10 nm bandwidth 0.15"/pixel 1x1 Arcmin
Field. The crescent is not completely uniform, some structure can be seen.
Uranus satellites 17/07/2004 - 02h45m53s Exposure: 56s (2
sec basic exposure) I filter, 0.15" per pixel, the set of stacked image
has a median seeing of 0.8 arcsec.
Uranus 17/07/2004 - 02h45m53s Exposure: 56s (2 sec basic exposure)
I filter, 0.075" per pixel, the 4" diameter shows some features.