A nice photo opportunity will be taking place on August 17th just after sunset. Head outside and look to the southwest for the crescent moon. Just a little to the lower right (southwest) from the moon will be brilliant Jupiter. Heading more to the west, Venus will be lighting up the sky. Enjoy!
Each August, the Earth passes through a stream of comet debris from Comet 109P/Swift-Tuttle. The comet will not be back our way until 2126… so… I wouldn’t wait up for that one. Along the orbital path, the comet has left behind small bits and pieces, most no bigger than a grain of sand. These run into our planet’s atmosphere and burn up due to friction. The result of this friction-filled reentry is a meteor, a rapid streak of light through the sky. This shower usually gives us about 60 meteors per hour at peak, and many fireballs: bright meteors that can even be bright enough to cast a shadow. How to see it?
- Pick a clear night closest to the peak, which is on August 12th/13th.
- Go to a dark sky site: avoid lights and cities. The darker, the better.
- Bring something comfortable to lie down on: sleeping bags are good.
- Bring food, drink, and bug spray if needed for your location.
- Spend the night time hours looking up at the sky! No optics required other than your eyeballs.
- Avoid lights! No cell phones. No flashlights. Your eyes take between 30-60 minutes to become dark adapted, and you lose that dark adaptation instantly if you see a light. Avoid lights!
- The shower appears to come from a spot in the sky in the constellation Perseus. This rises just before midnight, so best observing will be after that, into the morning hours.
- Have fun!
This is not for the faint of heart. You need to know how to use a CCD imager and your telescope. I write this here, because there are so many websites with INCORRECT information about this process. Some miss the point completely. All this does is mess with your head and mess with your gear. This method works. Trust me.
Polar Alignment with CCD
This is for permanent installations, as it can take up to 3 or 4 hours to complete the whole process to the point where your mount is perfectly polar aligned. The result is that you no longer have to worry about declination drift during imaging. You still have to worry about periodic error from your mount’s drive, but any good autoguider will take care of that. These instructions assume that you know how your CCD is aligned on the scope (which way is N, E, S, W on the images). In all cases, you will be monitoring North-South changes in a star’s position on your CCD images. IGNORE any east-west drift.
Polar Axis Altitude Alignment:
1. Manually polar align your mount to the best of your ability. Some mounts come with polar alignment scope in the polar axis shaft. Use it! This will actually get you close enough to take 5 to 10 minute integrations without doing the rest of this list! You will depend on your autoguider.
2. Aim your telescope at a star low on the eastern horizon and on the celestial equator (close is good). Faint stars are ok. You do not want them blooming.
3. Take 15 30-second long integrations of that star. Some people prefer to take one 5 minute long shot of the stars to see its path, but it works just as well to see the star’s position move due to drift via snapshots. DO NOT move the mount in any way during these shots. Just let the RA motor do its job.
4. Now to fix your drift! In this step you move the mount’s permanent polar axis depending on the way the star has drifted on your images.
a. If the star drifted north on your images, then move the mount’s polar axis down a tiny(!!) bit.
b. If the star drifted south on your images, then move the mount up a tiny(!!) bit.
5. Repeat steps 2 through 4 until you see NO DRIFT in 5 minutes. Want better? Go for longer. You will find that you can use the centroid tool in your image processing software and get excellent results in about 30-40 minutes.
Polar Axis Azimuth Alignment:
1. Aim your telescope at a star on the meridian and on the celestial equator.
2. Take 15 30-second long integrations of that star. Some people prefer to take one 5 minute long shot of the stars to see its path, but it works just as well to see the star’s position move due to drift via snapshots. DO NOT move the mount in any way during these shots. Just let the RA motor do its job.
3. Now it is time to fix your polar alignment’s altitude to perfection! Be sure to make VERY SMALL adjustments to the polar axis at this time.
a. If the star drifted to the north in your images, then slightly move the mount to the east.
b. If the star drifted to the south in your images, then move the mount to the west.
4. Repeat steps 2 and 3 above until there is NO DRIFT in your 5 minute series.
Congratulations! Your mount is polar aligned. You will likely not need to adjust this again until you swap out telescopes, have an earthquake (more common than you think!) or someone fiddles with a knob or two on your mount (also not all that uncommon as you think).
Now mid-March 2018 and there are planets in the sky! Here are some of the notable moments.
If you look to the west right after sunset you will catch bright Venus and fleeting (and fainter) Mercury. On March 18th, just after sunset, you might also be able to catch the very young, sliver moon, low on the western horizon.
Are you and early riser? Then you will be able to catch the other bright planets, Mars, Jupiter and Saturn.
The town of Casper, WY is now hopping along. A lot more people are here today. We started out with a visit to the Geology Museum on the southwest side of things. They have an excellent display on geologic time along with representative minerals and fossils from each period/era. They also have their very own T.rex skeleton, a nice surprise. It is being slowly picked out of the encasing rock….
So, there was a lot of good paleontology to enjoy there for sure!
Back into town, the place is swinging. Lots of people wandering about with geeky T-shirts… yes, these are eclipse watchers for sure. The town has closed off the central area for shops to show off their goods, for people to mill about, to have a quick bight to eat/drink, and relax in the summer sun, a hot summer sun, pushing to 90F. The skies today: crystal clear. Absolutely lovely.