Comets are truly remarkable members of the solar system. Believed to be debris left from the solar system's creation, they are a link to understanding the composition and formation of the solar system. Described as 'dirty icebergs', a comet's nucleus is an agglomeration of ices (such as water, carbon dioxide, ammonia), dust and rock particles. As a comet approaches the inner solar system, heating from the sun causes the ices to vaporize, releasing the gases, dust and particles. Solar radiation pressure pushes the released materials away, creating the coma and tails that are the signature feature of a comet. Comets are wonderful subjects for photography because they are very can rapidly change in appearance and are a beautiful example of the dynamic nature of the solar system. As they approach the sun, sudden increases in vaporization can release large chunks from the nucleus or create localized vapor jets, modifying the appearance of the coma and tail. Gravitational forces from close approaches to planets or the sun can break the nucleus into fragments, creating a multiple comet string. And severe interaction with the sun can cause the comet to completely vaporize and disappear. This album presents photographs of comets for the years 1996 through 2007. The comets are:

Hyakutake C/1996 B2 Hale-Bopp C/1995 O1 SWAN C/2006 M4 McNaught C/2006 P1 Holmes 17P

Proceeding each group of photographs is a description of the equipment used to obtain the images and exposure details.

HyakutakeHyakutake

C/1996 B2

1) Canon FTbN SLR with Canon FD 200mm f/2.8 Kodak Ektachrome 400 10 minutes Piggyback on Celestron 8-inch Schmidt-Cassegrain 2) Composite of three images: Canon FTbN SLR with Canon FD 300mm f/4, 2 minutes Canon FTbN SLR with Canon FD 200mm f/2.8, 1 minute Canon FTbN SLR with Canon FD 135mm f/2.5, 1 minute

All on Kodak Ektachrome 400 Piggyback on Celestron 8-inch Schmidt-Cassegrain 3) Canon FTbN SLR with Canon FD 50mm f/1.8 Kodak Ektachrome 400 5 minutes On stationary tripod 4) Canon FTbN SLR with Canon FD 200mm f/2.8 Kodak Ektachrome 400 5 minutes Piggyback on Celestron 8-inch Schmidt-Cassegrain Location: Monmouth Junction, New Jersey Lat: +40º 22' 38" Long: -74º 44' 28"

HaleHale--BoppBopp

C/1995 O1

1) Canon FTbN SLR with Canon FD 200mm f/2.8 2 minutes - Kodak Ektachrome 400 Piggyback on Celestron 8-inch Schmidt-Cassegrain 2) Canon FTbN SLR with Canon FD 135mm f/2.5 5 minutes - Kodak Ektachrome 400 Piggyback on Celestron 8-inch Schmidt-Cassegrain 3) Canon FTbN SLR with Canon FD 300mm f/4 2 minutes - Kodak Ektachrome 400 Piggyback on Celestron 8-inch Schmidt-Cassegrain 4) Canon FTbN SLR on Celestron 8-inch SCT 2000mm f/10 10 seconds - Kodak Ektachrome 400 5) Canon FTbN SLR on Celestron 8-inch SCT with 0.5x focal reducer

1000mm f/5 2 minutes - Kodak Ektachrome 400 6) Canon FTbN SLR with Canon FD 50mm f/1.8 15 seconds - Kodak Ektachrome 400 On stationary tripod 7) Canon FTbN SLR with Canon FD 85mm f/1.8 30 seconds - Kodak Ektachrome 400 Piggyback on Celestron 8-inch Schmidt-Cassegrain Location: Monmouth Junction, New Jersey Lat: +40º 22' 38" Long: -74º 44' 28"

SWANSWAN

C/2006 M4

1) Canon EOS 20D DSLR with Canon EF 24-105mm f/4L at 105mm ISO 1600 Stack of 4 15-second exposures On stationary tripod Location: Monmouth Junction, New Jersey Lat: +40º 22' 38" Long: -74º 44' 28"

McNaughtMcNaught

C/2006 P1

1) Canon EOS 20D DSLR with Canon EF 180mm f/3.5L Macro ISO 1600 Unknown exposure On stationary tripod Location: Monmouth Junction, New Jersey Lat: +40º 22' 38" Long: -74º 44' 28"

HolmesHolmes

17P

All photographs taken using Canon EOS 20D DSLR with Canon EF 100-400mm f/4.5-5.6L IS zoom lens on Vixen GPDX equatorial mount with SkySensor 2000 at ISO 1600 1) 100mm f/4.5, stack of 20 1-minute exposures 2) 400mm f/5.6, stack of 20 1-minute exposures 3) 100mm f/4.5, stack of 40 1-minute exposures 4) 400mm f/5.6, stack of 40 1-minute exposures 5) 100mm f/4.5, stack of 50 1-minute exposures 6) 400mm f/5.6, stack of 50 1-minute exposures 7) 100mm f/4.5, stack of 50 1-minute exposures 8) 400mm f/5.6, stack of 25 1-minute exposures 9) 100mm f/4.5, stack of 50 1-minute exposures 10) 400mm f/5.6, stack of 50 1-minute exposures 11) Composite of the 5 100mm f/4.5 photographs Location: Monmouth Junction, New Jersey Lat: +40º 22' 38" Long: -74º 44' 28"