2017 Gallery

2017 featured many adventure recorded in the photos of the year. Fun to look back and relive the expereince…

A Better Solar Water Heater Electric Back-Up Timer

Another little problem around the house that can use a little creative circuitry to make it better. Do I really have to do it? No. I do it because I can, and because it is fun!

Solar Water Heater Back-Up Timer
A hot water heater timer setup for a solar water heater.
This time it is the electric back up heater for my solar hot water heater.

In Waikoloa solar hot water is an obvious addition to the house, we had it installed within a couple months of moving in. Considering electric power is about $0.40/kWh on the island, and tropical sunlight is quite intense, the use of solar to heat our water has been good money saving move… Long, hot showers with no guilt!

Once or twice a year we will get a period of heavy clouds and the water temperatures will fall to the point we need to turn on the electric back-up heating element in order to have that hot shower. Like most solar setups the storage tank has a electric element that will heat the water when needed.

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Astronomers Shed Light on Formation of Black Holes and Galaxies

W. M. Keck Observatory press release

Stars forming in galaxies appear to be influenced by the supermassive black hole at the center of the galaxy, but the mechanism of how that happens has not been clear to astronomers until now.

“Supermassive black holes are captivating,” says lead author Shelley Wright, a University of California San Diego Professor of Physics. “Understanding why and how galaxies are affected by their supermassive black holes is an outstanding puzzle in their formation.”

Image of the quasar host galaxy from the UC San Diego research team’s data. The distance to this quasar galaxy is ~9.3 billion light years. Credit: A. Vayner and team
In a study published today in The Astrophysical Journal, Wright, graduate student Andrey Vayner, and their colleagues examined the energetics surrounding the powerful winds generated by the bright, vigorous supermassive black hole (known as a “quasar”) at the center of the 3C 298 host galaxy, located approximately 9.3 billion light years away.

“We study supermassive black holes in the very early universe when they are actively growing by accreting massive amounts of gaseous material,” says Wright. “While black holes themselves do not emit light, the gaseous material they chew on is heated to extreme temperatures, making them the most luminous objects in the universe.”

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Winter Solstice

Winter solstice occurs today at 16:28HST. Today the Sun will occupy the most southerly position in the sky of the year. The term solstice comes from the Latin terms Sol (the Sun) and sistere (to stand still). On this day the Sun seems to stand still as it stops moving southwards each day and begins move to the north. This is the first day of winter as marked by many cultures in the northern hemisphere. Alternately, this is the first day of summer for those folks in the southern hemisphere.

2017 Solstices and Equinoxes
  UT HST
Perihelion Jan 4 14:18UT Jan 4 04:18HST
Vernal Equinox Mar 20 10:29UT Mar 20 00:29HST
Summer Solstice Jun 21 04:24UT Jun 20 18:24HST
Apehelion Jul 3 20:11UT Jul 3 10:11HST
Autumnal Equinox Sep 22 20:02UT Sep 22 10:02HST
Winter Solstice Dec 21 16:28UT Dec 21 06:28HST
Source: USNO data Services

 

Mercury at Inferior Conjunction

Today Mercury will be at inferior conjunction. After today the planet will reappear in the dawn, rising high enough from the Sun’s glow to be seen around the end of the year.

Mercury Transit 9May2016
Mercury transiting the Sun on May 9, 2016. Celestron C8 and Canon 6D at f/10.
Inferior conjunction is when the planet passes between the Sun and the Earth. As such the only planets to see inferior conjunction are Mercury and Venus. A transit is possible if the planet passes directly in front of the Sun, but normally this alignment does not occur, the planet passing above or below the Sun as seen from the Earth. There are no transits of Mercury in 2017, the next will be Nov 11, 2019.

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Geminids

The annual Geminid meteor shower has become one of the most reliable annual meteor showers. Known for bright and slow moving fireballs the Geminids can provide a good reason to spend a few hours outside on a December night. This shower has routinely provided rates above 100 meteors per hours in past years, this year should be no exception.

Leonids in Orion
A pair of Leonid meteors streak through Orion, combination of 10 x 15s frames
First observed over 150 years ago this is a interesting meteor shower. The parent body for the Geminids is not a comet as with most showers, but rather the asteroid 3200 Phaethon. It is somewhat of a mystery how this mostly rocky body gives rise to the debris stream needed to generate a meteor shower. The asteroid does orbit well inside the orbit of Mercury every four years, where intense solar heating may heat trapped ice and liberate loose material from the surface.

The peak is expected to occur around December 14, 06:30UT. For viewers here in Hawaiʻi this occurs on the evening of December 13th. The Geminids feature a broad peak, with high rates for nearly 24 hours, thus allowing the all time zones a decent chance to enjoy the show.

There should be no substantial moonlight to drown out this years showing, dark skies to allow even the faintest meteors to be seen. The Moon is a thin waxing crescent, 1% illuminated on the morning of the 13th, essentially new.

The Geminid radiant rises round 8pm, thus meteors should be visible all night long. You can stay up late or set the alarm early, your preference. Southern viewers will have to wait until around midnight for the constellation Gemini to rise, making this a morning shower.

Watching meteors requires no more equipment than your eyes and a dark sky, and can be enjoyable for just about anyone. Well? It is December, you should probably add a warm coat to the equipment list.