Page 54 - Astronomy - October 2017 USA

The author considers this image of Saturn —
taken June 18, 2016, at 3h41m UT — the finest
he’s ever captured with his 14-inch telescope.
Note the great detail visible within the ring processing routines that allow imagers to cameras, the procedure is far less frantic.
system and on the planet’s globe. compensate for rapid planetary rotation, Using image de-rotation in WINJUPOS
thereby creating higher-quality images. allows a much longer capture window
(http://jupos.org/gh/download.htm) overall (up to 15 minutes), making the pro-
bands. By far the best for planetary imag- cess much easier.
ing is the 889-nanometer methane band Image the giant In terms of video frame rate, shooting
filter. This narrowband IR filter focuses on The solar system’s largest planet is the jewel through the R and G filters at around
sunlight absorption due to methane in the of the night sky. Jupiter is one of the few 80 fps should work well. You’ll have to use
atmospheres of the giant planets and is truly dynamic astronomical objects that a slower rate when you image through a B
especially useful for Jupiter and Saturn. can be studied closely with amateur equip- filter, though. Because most camera chips
One particularly nice aspect of plan- ment. Its huge size means it presents a large are more sensitive to red light than blue,
etary imaging today is that many software apparent disk as seen from Earth, and even your frame rate in blue may need to be as
packages you’ll need are available for free. small telescopes can show considerable much as one-half that as with the other
Below you’ll find a few of the key titles: detail. It also rotates rapidly — a jovian filters. Finally, you’ll need to stack at least a
• Firecapture. This program is by far day lasts 9 hours, 55 minutes — so you can thousand frames to create a reasonably
the most popular for planetary camera see much of the planet during just a single noise-free result that will allow sharpening.
operation. It supports almost every model night under the right circumstances. Narrowband methane filters also can
and has an advanced and well-designed Jupiter’s rapid rotation makes it chal- help bring out lots of detail. Such filters are
user interface. (www.firecapture.de) lenging to photograph. The time window typically quite expensive but a worthwhile
• Autostakkert! For aligning and available before rotation begins to smear investment for those keenly interested in
stacking the frames taken by today’s plan- detail is quite short compared with the imaging Jupiter with the highest quality.
etary cameras, this software leads the way. other planets. For those using large aper-
(www.autostakkert.com) tures in good seeing conditions, 60 seconds Image the ringed world
• Registax. This program has gone is probably the upper limit per single cap- With its captivating ring system, Saturn
hand in hand with the advancements we ture. For an RGB sequence, 3 minutes is is without question one of the most spec-
have seen in planetary imaging over the the upper limit before too much rotation tacular sights visible through any telescope.
past decade or so. It allows both image occurs between the color channels. Larger amateur scopes can capture a
alignment and processing of image data. Having a smooth routine in place is wealth of detail across the globe and rings.
(www.astronomie.be/registax) really important to use every second for Minor storms appear as small bright
• WINJUPOS. Originally intended to RGB imaging of Jupiter, and this only spots and are typically quite frequent.
measure the position of atmospheric fea- comes from practice. Such a routine also Larger storms also can erupt, such as dur-
tures within the jovian atmosphere, this helps render the tones of the planet accu- ing the 2011 apparition when observers
program now contains sophisticated rately. Of course, for those using color were treated to a planet-encircling storm,

54 ASTRONOMY • OCTOBER 2017