Author: Andrew

An electrical engineer, amateur astronomer, and diver, living and working on Mauna Kea, Hawai'i.

Uranus at Opposition

Today the planet Uranus will pass through opposition, directly opposite the Sun in our sky. The planet will be well placed for observation all night long, rising at sunset, transiting at midnight, and setting at sunrise. If you are looking to observe Uranus, it is currently shining at magnitude 5.7 in the center of the constellation Pisces.

Uranus
The planet Uranus as it appears in a mid-sized telescope
As the outer planets Uranus and Neptune move so slowly across the sky, the timing of oppositions is driven by the Earth’s orbit and occur each year at nearly the same time. The orbital period of Uranus is 84.1 years, taking the better part of a century to circle the celestial globe once.

Mercury at Superior Conjunction

Today Mercury will be at superior conjunction. After today the planet will reappear in the evening sky, rising high enough from the Sun’s glow to be seen around the end of the month.

Mercury Transit 9May2016
Mercury transiting the Sun on May 9, 2016. Celestron C8 and Canon 6D at f/10.
Superior conjunction is when the planet passes around the far side of the Sun as seen from Earth. For a few weeks the planet will be lost in the Sun’s glare, hidden from view.

As Mercury is on an orbit inside that of Earth’s it will see both inferior and superior conjunctions as it passes from the evening sky to the dawn sky and back again.

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It was one of those weeks…

It was one of those weeks.

Keck 2
The Keck 2 telescope, iPhone photo processed in Prisma
It did not look like it was going to be a bad week. The schedule was for a light week with nothing serious envisioned. Better yet, Tuesday was scheduled to be our departmental retreat, a day at the beach with the operations crew, all good.

One. Deb is having a bad spell. With little warning I took off Monday afternoon to drive her down to Kona to spend a couple hours in the infusion lab for medication.

Two. Monday would just not die easily… The phone calls began just after sunset. The Keck 1 hydraulic bearing system would not come on properly, shutting down just after the main pump came online. It became quickly apparent that I would be joining John and Justin for a trip to the summit in the middle of the night.

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Reef Fish Gallery

Leaf Scorpionfish (Taenianotus triacanthus) crouched in finger coral
A commerson’s frogfish (Antennarius commerson), photo by Pete Tucker, used with permission
A Cheekspot Scorpionfish (Scorpaenodes littoralis) near the shore in 4′ of water, Mahukona
A cleaner wrasse (Labroides phthirophagus) in an overhang filled with red sponges
Teardrop butterflyfish (Chaetodon unimaculatus) peeks out from under cover
Orangespine unicornfish (Naso lituratus) at 25ft depth, Suck-Em-Up Cave
Hawaiian red lionfish (Pterois sphex) on a cave ceiling
An Arceye Hawkfish (Paracirrhites arcatus) hides from the photographer deep in a coral head
Twospot Lizardfish (Synodus binotatus) at 30ft depth, Puakō
A female whitley’s boxfish (Ostracion whitleyi) in the coral at 40′ depth, Kaloko
Commerson’s Frogfish (Antennarius commerson) at 25′ depth
Redbarred hawkfish (Cirrhitops fasciatus) perched in a reef crevice
A trumpetfish (Aulostomus chinensis) considers the camera
Tinker’s butterflyfish (Chaetodon tinkeri), photo by Pete Tucker
Ornate butterflyfish (Chaetodon ornatissimus) photographed during a night dive at Puakō
A group whitebar surgeonfish (Acanthurus leucopareius) of clean algae and parasites off a green sea turtle (Chelonia mydas)
A dragon wrasse, actually a juvenile rockmover wrasse (Novaculichthys taeniourus) at 40′ depth, Kaloko
A longnose butterflyfish (Forcipiger flavissimus) in nighttime coloration during a night dive at Puakō
Flowery Flounder (Bothus mancus) on the reef at O’oma
Bluestripe squirrelfish (Sargocentron tiere) in a small cave at Pentagon
A bright red painted frogfish (Antennarius pictus) at 25′ depth, Puakō
A trumpetfish (Aulostomus chinensis) considers the camera
A pair of Goldring Surgeonfish (Ctenochaetus strigosus) at 35ft depth at Eel Cove
A young trumpetfish (Aulostomus chinensis) hovers in the arms of a large antler coral (Pocillopora eydouxi)
Racoon butterflyfish (Chaetodon lunula) at 25ft depth, Hoover’s Tower
Brick Soldierfish (Myripristis amaena) in a cave at Puakō
A racoon butterflyfish (Chaetodon lunula) in a small cave at Golden Arches
A devil scorpionfish (Scorpaenopsis diabolus) at The Hive

Consequences of a Bad LED

A bad indicator LED, a simple ten cent part brought the Keck 1 telescope to a stop this last week.

Logic Card
A section of the AAA logic card.
How can that be? Usually an indicator is just that, an indicator. While an LED may indicate a problem it is rarely the cause of the problem.

I was getting ready to leave the summit when the radio started to speak words of concern, it sounded like something was not working, an instrument rotator?

Worse, the Keck 1 computer room hosted a veritable crowd, from the summit supervisor to all of the techs. Yeah, this was not good, why are they all looking at me? Oh, h%#*!

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