Yellow Tang
Author: Andrew
An electrical engineer, amateur astronomer, and diver, living and working on the island of Hawaiʻi.
Mercury at Superior Conjunction
Today Mercury is passing through superior conjunction, passing around the far side of the Sun as seen from our earthbound vantage point. This fast moving planet will reappear in the sunset in about a week, rising towards maximum elongation on October 20th.
This will be a good apparition of mercury reaching over 24° from the Sun.
| Mercury Events for 2019 | |||
|---|---|---|---|
| Apparition | Date | Elongation | Magnitude |
| Evening | Feb 27 | 18.1°E | -0.2 |
| Morning | Apr 11 | 27.7°W | +0.6 |
| Evening | Jun 23 | 25.2°E | +0.7 |
| Morning | Aug 9 | 19.0°W | +0.3 |
| Evening | Oct 20 | 24.6°E | +0.1 |
| Morning | Nov 28 | 20.1°W | -0.3 |
| Data from the Mercury Chaser’s Calculator by John Walker | |||
Mars at Superior Conjunction
Today mars is passing through superior conjunction, passing behind the Sun as seen from our earthbound point of view.
Mars will reappear in the dawn around the end of September, a star like object low on the horizon, just above the glow of sunrise.
Mars will spend the remainder of 2019 and much of 2020 in the dawn sky, reaching opposition on Oct 13th, 2020.
Gecko and Plumeria
Laboring on Labor Day
The labor day weekend project? Replacing a few more rotten boards in the lanai.
This has been an ongoing project for years, including a few more boards to replace this summer. Over the last few weeks I have replaced half a dozen boards in the lanai.
I write this as I wait for paint to dry. There are three more big gaps in the lanai waiting for new boards. Those boards have been cut to size, drilled, and are almost ready to screw into place. Deb bought me another box of decking screws last time she was in Kona, should have this done shortly.
Unfortunately the original builders scrimped a bit when building the lanai. No paint on the ends of the boards, no paint underneath, and no paint on the joists. Where the lanai is undercover that has not been a problem, where it is exposed to the weather that has resulted in a fair amount of damage.
Unlike the carpenters who did the original work, I am painting each board on all surfaces before installation. I also clean and paint the top edges of the joists underneath while they are exposed. This should slow down the damage due to exposure.
The last challenge is to get the gaps right. Much of the lanai is nicely spaced between the boards. There is a zone where the gaps are all wrong, the boards right against each other. This is also right where the drip line is from the roof and most of the damage is. The result is a lot of careful measurement and ripping the boards to get the gaps looking good again.
I have two or three more boards identified as needing replacement, but not in any great hurry. They can wait for another weekend. Just need to wait for the latest round of paint to dry and I can screw the next three boards into place.
Getting a Mirror Re-Coated
The classic Cave Astrola telescope has become my roll-out, quick observing session ‘scope, often found in my driveway. I have also used it a few times at darker sites when I expect the weather to be damp or dewy as a Newtonian is more protected.
While the restoration job was finished some time ago, I never got around to re-coating the optics. Meanwhile the telescope has seen good service on many occasions as I enjoyed this fun-to-use instrument.
The optics did need some attention… The primary mirror from the Astrola appeared to have not been re-coated since it was made in 1978. Thus the aluminum coating was over 40 years old. While the coating looked bad, it was still serviceable, producing reasonable images.
Still, the loss of light due to the old aluminum coating was probably reducing the effectiveness of this 8″ telescope to something more like a 6″ telescope. I had meant to get it re-coated some time ago, but we know how these things work.
Continue reading “Getting a Mirror Re-Coated”New Moon
New Moon will occur today at 00:37HST.
Tomorrow, August 31st offers the best conditions for a weekend observing session this month. Get out and enjoy the dark!
Continue reading “New Moon”Were the telescopes built without permits?
This is another fairly common myth about the existing telescopes on Mauna Kea, that most of the telescopes were built without permits or issued “after-the-fact” permits after construction.
This is another myth built on a kernel of truth, the two earliest of the remaining thirteen telescopes were built without proper conservation district use permits in place. What is now Hoku Kea was built by the Air Force Cambridge Research Laboratories and given to the university a couple years later. The UH88 was built by the University of Hawaii in 1968.
As this was the State of Hawaii building on state land, apparently things were a bit lax. In retrospect this is no surprise, the state government was scarcely a decade old at this point and many of the administrative rules and regulations we now take for granted were still being written and implemented.
This is where the myth comes in, as somehow the other telescopes are accused of the same issue. The claim often made is that “most of these structures were un-permitted”. This is often claimed as part of the evidence for mismanagement by the university.
This is incorrect… All of the remaining telescopes were built with proper permits in place. The key permits are the Conservation District Use Permits or CDUP’s that allow the use of state land on the summit of Mauna Kea. Permit numbers and dates are listed in the table below…
Continue reading “Were the telescopes built without permits?”Crabber
Give Me Enough Rope
Longtime readers will know that our household is ruled by cats. This means that some household chores have higher priority than others. One of the odd chores that has to be done every few years is re-wrapping the scratching pole with rope.
Yes, the cats use the pole, usually more than they use other soft surfaces around the house. The result is a shredded mess of sisal fiber hanging from the pole. Eventually it gets bad enough I just cut it away and re-wrap the pole in rope.
Conveniently a 50′ package of 1/2″ rope from the local hardware store neatly does the job. Just an hour spent cutting the old rope away, then wrapping the pole neatly with a drop of glue to secure the end down inside the tube… Done, with happy cats busily clawing away at the fresh rope.
How long will it last?