New Moon

Young Moon
A very young moon over Waikoloa, this is only 26 hours after new, visible to the unaided eye as a sliver in the fading glow of sunset
New Moon will occur today at 15:45HST.

This new moon will feature a total solar eclipse that sweeps from Indonesia across the central Pacific. It will be visible as a deep 50% plus eclipse in Hawaii.

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Solar Eclipse Reminder

Partial Solar Eclipse
A partial solar eclipse from Kawaihae, 9 May 2013
Just a reminder that later today there will be a solar eclipse. This is a total with the path of totality passing north of the main Hawaiian Islands near Midway. For the Big Island this will be a deep partial, about 55%.

Solar Eclipse Data for March 8th, 2016

  Mag Begin Max End
Hilo 55% 16:37 17:37 18:32
Honolulu 63% 16:33 17:36 18:33
Lihue 67% 16:31 17:35 18:33
Kahului 60% 16:35 17:37 18:33
Kona 56% 16:36 17:37 18:32
Mauna Kea 56% 16:37 17:37 18:32
Midway Is 97% 16:04 17:20 18:29
 
All times HST
Source: EclipseWise Interactive Map

 

Fungus on Glass

The tropical environment of Hawaiʻi is not kind to optical instruments. Tropical humidity can cause a host of issues ranging from corrosion of metal parts to decay of wooden and cardboard telescope structures. For those of us who build and use small telescopes the issues of tropical heat and humidity are rather concerning.

Fungus on Glass
Fungus colony on a small achromatic lens surface
Worst of all is the fungus. Impressively there are species of fungus that can grow and thrive on clean optical surfaces. It is hard to imaging a more hostile place to grow, seemingly devoid of nutrients and the moisture necessary for life.

I have seen camera lenses lost to the white fungus. A friend once showed me a Canon 70-200 f/2.8 L, a $2000 lens, with fungus covering internal elements. Even on the “dry side” of Waimea the humidity was high enough to allow fungus to destroy this lens.

The problem is not an issue on the summit of Mauna Kea. The high altitude air typically exhibits a relative humidity of less than 10%. Several references note that a humidity of above 70% is needed to promote fungal growth on optics. We see no issues with fungal damage to the mirrors or instruments on the big ‘scopes.

Below the tropical inversion layer (about 6-7k feet) it is another issue entirely. Near sea level, where most of us live, humidity can remain above 80% much of the year. The warm and humid conditions of these islands are idea for growing anything, including the omnipresent fungal gardens that create the smells of a tropical landscape. Fungus is inescapable in this world, the spores drift on the wind and an stay dormant for decades, anywhere conditions are suitable fungus will grow.

The possibility of equipment damage was a major element in our buying a house. Waikoloa is located within one of the driest areas of the island. The humidity typically hovers in the 50’s, dry enough that I have had no issues with the multiple telescopes stored in the garage. Still, I do inspect stored equipment periodically, looking for the dreaded white fungus or other damage wrought by this tropical climate.

It is not a single species of fungus responsible for the problem. Apparently quite a few species are able to colonize an optical surface. Looking through the literature I find referenced to multiple species that can grow on optical glass…

The fungi which grow in optical instruments belong to the groups Phycomycetes, Ascomycetes and Fungi Imperfecti. The following species were frequently isolated from instruments which had been in New Guinea: Penicillium spinulosum, Thom.; P. commune, Thom.; P. citrinum, Thom.; Aspergillus niger, Van Tiegh.; Trichoderma viride, Pers. ex-Fr.; Mucor racemosus, Fres.; and M. ramannianus, A. Moeller. So far, Monilia crassa has not been isolated from Australian instruments, although Dr. W. G. Hutchinson (5) of the United States, found this to be a common species in the Panama zone, and it has also been recorded as frequent in West Africa by Major I. G. Campbell. – J.S. Turner, et al.1

I admit that the fungus can be pretty, in an odd sort of way considering the damage. Under a microscope it appears lacy, the mycelium fibrils growing across the glass in search of more nutrients to support the colony. In the center small round fruiting bodies are the launching point for new fungal spores.

I recently had another round of battle with fungus while restoring a collection of instruments that had been stored in a garage on the side of Hualalai. The high humidity had wrought impressive damage on both the optics and metal components of the telescopes. And there is fungus! Found in the eyepieces and on the telescope mirrors. During the cleaning and restoration of the instruments I found it necessary to completely dismantle many optical assemblies just to remove and kill the fungus. I some cases I was in time, but not completely, it is not without regret that I throw a $400 eyepiece into the trash.

Dealing with the fungus is imperative, cleaning and killing the growth before severe damage can be done may save the equipment. If the growth is severe enough the glass surface and the coatings can be damaged. Apparently the fungi can excrete hydrochloric acid, etching the surface and creating permanent damage.

Fungus on Glass
Fungus colony on a small achromatic lens surface
Minor damage may not be enough to ruin the device. It actually takes a great deal of damage to appreciably affect the performance of most optics. A few small specks of damage remaining on the surface after cleaning may not be noticeable. Inspection of each spot of damage with a microscope can be useful, Sometimes it is clearly damage of the surface and irrepairable. I have also found hard deposits that at first glance appeared to be damage under the core of fungal colonies that remained after cleaning. These may be removed using a soft wooden tool like a toothpick or chopstick.

Killing the fungi requires a solvent that will both kill the fungus while not damaging the optical surface. I find references to both alcohol as well as other solvents. A mix of 50/50 hydrogen peroxide and ammonia is recommended by some references. Along with cleaning the glass I am careful to soak all of the structural elements as well. The tube, the spacers and lock-rings can all harbor minuscule colonies or spores awaiting suitable conditions to grow again.

Optical fungicide solutions tend to be expensive and hard to obtain, but they are available from some optical equipment manufacturers. Alternatively, you can use a 50/50 mix of hydrogen peroxide (H2O2) and ammonia (NH3). Usually, 5 ml of each is adequate (10 cc in total). Mix just prior to use and do not store the mixed product. – Ismael Cordero, Community Eye Health Journal2

Living in a warm humid environment one must be vigilant and ready to deal with issues when found. Examine optics regularly, keep a can of WD-40 next to the tool box (and use it), store optics and electronics with plenty of ventilation and reduce the humidity to well below 70% if needed. Extra vigilance to preserve valuable equipment is the price of living in paradise.

  1. Tropic-Proofing of Optical Instruments by a Fungicide, J.S. Turner, E.I. McLennan, J.S. Rogers, & E. Matthaei, University of Melbourne, Nature 158 (Oct. 5, 1946) 469-473.
  2. Fungus: how to prevent growth and remove it from optical instruments, Ismael Cordero, Comm Eye Health Vol. 26 No. 83 2013 pp 57

A Leap Day

Today is February 29th, that odd date that only occurs every four years.

The reason for a leap day inserted into the calendar, the existence of February 29th, is ultimately astronomical. Perhaps a little explanation is in order…

We originally defined days as the time it takes the Earth to rotate. While we define years as the time it takes the Earth to orbit once around the Sun. The problem is that these values do not divide evenly into one another.

Mauna Kea Sunrise
Sunrise seen from the summit of Mauna Kea

The Earth takes about 365.24219 days to obit the Sun, when measured by the Sun’s position in the sky, what is called a tropical year. There are different ways to measure a year, but if one is concerned with keeping the seasons in sync with your calendar, then you are interested in tropical years.

It is that bunch of decimals, the 0.24219 etc., that is the problem, every four years the count drifts out of sync by roughly one day. The insertion of an extra day every four years helps bring the calendar back into synchronization with the orbit of the Earth and with the seasons.

Even leap years do not quite fix the problem as 0.24219 is close, but not quite 0.25 or one quarter of a day. Thus additional corrections are needed… Enter leap centuries.

Our current calendar was instituted by Pope Gregory XIII in 1582, setting up a standard set of corrections for the fractional difference between the length of a year and the length of a day. Scholars knew that errors had been accumulating in the calendar for centuries, resulting in a drift of several days. Religious authorities were concerned that this drift had displaced important celebration in the church calendar, in particular the celebration of Easter. After much argument it was decided to reform the calendar. The current solution was devised by a number of astronomers, including Aloysius Lilius, the primary author of the new system.

The Gregorian Calendar uses an extra day in February every four years, unless the year is divisible by 100, then there is no leap leap day that year. However, if the year is divisible by 400, then it is a leap year. While this may sound odd, it does create a correction much closer to the ideal value of 365.24219 days per year.

I am a geek, so let us put that into code…

if (year modulo 4 = 0) then
  if (year modulo 100 = 0) then
    if (year modulo 400 = 0) then
      leap= True
    else
      leap= False
  else
    leap= True
else
  leap= False

 

Even this is not perfectly precise. The correction is close but will drift given enough time. The length of a tropical year also changes slowly over time. We will eventually have to add another correction to keep the calendar and the seasons in sync. But not for a few millennia, good enough, for now.

As 2016 is divisible by four and not divisible by 100, there will be a leap day added to the end of this February… Today.

Mauna Kea Messier Marathon March 12

We are good to go! I have the DLNR permit for using the site. We will hold the Mauna Kea Messier Marathon 2016 on the evening of March 12 at the Ka’ohe observing site.

GyPSy in the Night
The 11″ NexStar GPS telescope, GyPSy set up at Ka’Ohe
Sunset: 18:31 HST
Astronomical twilight ends: 19:44 HST
Astronomical twilight begins: 05:19 HST
Sunrise: 06:32 HST

Please arrive before sunset so as not to annoy other observers with lights and dust, allowing a few extra minutes to find the setup site. This will provide plenty of time to set up gear and have a picnic dinner. I hope to be at the site around 5:30pm. I will sign the group in at the check-in station with the permit number, you need not sign in.

For those who wish to marathon I will have a checklist available for the effort. There are a lot of MM checklists, the one I provide is optimized for our 20N latitude which changes the priority of the evening and morning objects. If you do not want to participate, just come to observe.

If you are participating in the MM I would also suggest a low-power, wide field instrument. Smaller telescopes are actually better at this pursuit than larger. For MM I leave the 18″ at home and bring a 6″ telescope. Any finding aids are acceptable, including GOTO. If you are a purist like me? I will use nothing but a chart and a Telrad to locate the objects.

The site is to be found along the old Saddle Road just above the Kilohana hunter check in station. There is a line of pine trees a couple hundred yards above the gate, I plan to set up on the makai side of the trees where you will find a large flat area and a big pile of gravel stockpiled. A precise location and Google map for the Ka’ohe site can be found here.

A reminder that the DLNR permit has a few restrictions, nothing we would not do anyway… No open flame, no hunting, and please keep the area clean.

Now all we need is clear weather for a successful Marathon!

Classic Coke

One of the unexpected surprises I had when traveling in Nicaragua was the Coca-Cola. In a country where drinking the water was somewhat hazardous, bottled water and drinks were a good option. Not that this was much of a problem, Coca-Cola was sold everywhere, little street vendors always had a cooler of sodas. As anyone who knows me will tell you, my one dietary vice is coke.

Classic Coke
Mexican bottled Coca-Cola bought at Costco in Hawaii
The standard price was about 20 cordoba, about 70 cents in US dollars. In the little streetside shops I paid C$15 for a bottle, in tourist areas the price jumped to C$20, while the hotel in Managua wanted C$40. If you bought the glass bottles be sure to get the bottle back to the vendor, there is a deposit.

The reason the coke tasted better in Nicaragua was simple… The formula is mixed with cane sugar in place of the corn syrup used in the United States. The taste difference is remarkable and to my palate much improved by the difference. While traveling I found myself buying a bottle or two each day. Eventually it would be back to the US and back to corn syrup.

I did miss the coke I had found in Central America. In response to my frustrated complaint about Coca-Cola one day my wife informed me that you can buy the real stuff here on the island. What? She let me know that imported Coca-Cola was available at Costco. What?

To prove the point she brought some home. Sure enough… Coca-Cola bottled in the classic glass bottles and imported from Mexico. Reading the ingredients quickly reveals that the soda is made with cane sugar, not corn syrup. Even better, it tastes the same as the cola I bought in Nicaragua.

Refurbishing a TeleVue Renaissance Mount

I have already posted about the restoration of an orange tube C8. That was only part of the story, the telescope is paired with a TeleVue Renaissance mount that was in the same poor condition as the optical tube. The mount required the same treatment, a complete tear down and restoration to reverse the ravages that tropical humidity had wrought upon the metal parts.

RA and Declination Axis
The RA and declination axis removed from the mount for further disassembly and restoration
Corrosion was the issue. While the mount was mostly functional, it was looking horrible. The aluminum under the paint was corroding into a fine white powder. Most of the screws were quite rusted along with the counterweight shaft where the chrome was flaking away and the rust spreading. If allowed to continue the mount would soon be the piece of junk it looked like. There was something wrong with the clutches as well, they do not lock firmly and needed to be inspected.

The mount was sold by TeleVue in the 1980’s paired with their APO refractors. The mount is actually a re-labled unit manufactured by the Japanese firm Carton Optics as the model Super Nova or RSM2000. Well regarded by amateur astronomers you can find postings of well used and beloved mounts still in use thirty years later. Examining the mount I find I agree with those who like it. There is much to love in the solid smooth motion, this looks to be worth the effort of restoration.

Thus I set about the task of stripping down the mount into component pieces… Of the rusted hardware only one screw required drilling out, the hex drive head stripping when I tried to remove it. Fortunately I again had the proper tools, a set of easy outs to remove the remains of the screw after I had drilled the head off. I was able to remove the screw without any damage to the aluminum castings.

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Visitar el Volcán

I do like exploring volcanoes. As I live on an active volcano, with three other active volcanoes visible on the horizon, this sort of exploration is something I am regularly able to indulge myself with. The fifth nearby active volcano can not be seen from home, it takes a two hour drive to reach, a worthwhile trip as it is the one that is currently erupting. Since I have so many volcanoes in my life why would I want to visit another one? Because I love volcanoes!

Volcán Masaya
Looking down on the plume of volcanic gasses issuing from Santiago Crater at Volcán Masaya
Masaya is an active volcano just south of the capital of Nicaragua. It is part of a chain of volcanoes that dominates the landscape of the country. It is also easy to reach, part of a national park just a few miles off a major highway. You can drive right to the crater rim and look down into the pit.

While Masaya is not currently hosting any major activity it is home to an ephemeral lava lake and emits a steady plume of volcanic gasses. In many ways it is similar to visiting the Halemaʻumaʻu crater at Kilauea, a large pit with a plume of gasses. Like Halemaʻumaʻu, these craters are part of a larger volcanic edifice. There are three pit craters including San Fernando, Santiago, Nindiri and San Pedro that occupy the top of a complex of cones at the center of the caldera. The Masaya caldera is about seven miles wide with a large lake at the southeastern end. The last major eruption and lava flow was in 1670, with current activity confined to outgassing and the occasional ash plume.

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