Object: Comet C/2004 Q2 Machholz and M45
Date: 1/7/05, 9:00 - 9:50pm MST
Location: My backyard - Las Cruces, NM
Tracking: Camera piggybacked on an LX-200 ( unguided )
Camera: Canon Digital Rebel with Canon 100mm f2 lens @f2.5 and LPS filter
Exposure: 10x2 minute ISO 1600 stack combined with a 10x2 minute ISO 800 stack, 45 degrees F
Processing: ISO 1600 frames calibrated then all frames aligned using reference stars and stacked using ImagesPlus.  Result was aggressively stretched to enhance the dim ion tail and the background gradient was removed using PhotoShop.  Final smoothing filter applied using SBNR2
Comments: This image was captured as Comet Machholz was near closest approach to M45 with the nucleus roughly 2 degrees west of the cluster.  The comet displays two tails in the image; a long ion tail of charged particles pointing away from the Sun and a dust tail pointing back along the orbital path (down in the image.)  The ion tail dimmed sometime on the seventh, prior to the shot, but can be seen faintly crossing the upper part of the cluster.   This week marks the comet's closest approach to Earth (52 million km.)  For an inverted version of the image, click here. 

© Dave Dockery 2005