Full Moon

Full Moon
Full Moon taken 27Aug2007, 90mm f/12 APO and Canon 20Da
Full Moon will occur today at 05:47HST.

This full Moon will be a perigee full Moon, with the Moon appearing a bit larger and brighter. Today lunar perigee occurs about 17 hours of full, producing a full moon that is about 12% larger and 30% brighter than if full occurs while the Moon is at apogee.

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Snow on Mauna Kea?

The forecast looks promising. Not for observing, we lost most of the night last night to fog and clouds, the rest of the week looks worse. It does look like we may get some snow this week. Checking the cameras there are already a few flakes coming down, just a degree or so too warm to stick.

Winter is here… Snow for Christmas?

First Snowflakes of Winter
A few snowflakes in the camera… Snow for the holidays?

Update! Sticking now…

First Snow of Winter
The first snowfall of the 2017-2018 winter season atop Mauna Kea.

Mercury at Maximum Elongation

Today Mercury will be at maximum eastern elongation, as high in the evening sky as it will appear for this current apparition. After today the planet will slide back into the sunset, passing through inferior conjunction on December 12th to reappear in the morning sky 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.
Mercury typically completes three morning and three evening apparitions in each year. While the innermost planet never gets very far from the Sun, maximum elongation represents the best time to observe Mercury as high in the sky as possible.

There are no transits of Mercury in 2017, the next will be Nov 11, 2019.

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Alaska Gallery

Astronomers Discover A Star That Would Not Die

W. M. Keck Observatory press release

An international team of astronomers led by Las Cumbres Observatory (LCO) has made a bizarre discovery; a star that refuses to stop shining.

Supernovae, the explosions of stars, have been observed in the thousands and in all cases they marked the death of a star.

Supernova
Artists impression of a supernova. Credit NASA/ESA/G. Bacon (STSCI)
But in a study published today in the journal Nature, the team discovered a remarkable exception; a star that exploded multiple times over a period of more than fifty years. Their observations, which include data from W. M. Keck Observatory on Maunakea, Hawaii, are challenging existing theories on these cosmic catastrophes.

“The spectra we obtained at Keck Observatory showed that this supernova looked like nothing we had ever seen before. This, after discovering nearly 5,000 supernovae in the last two decades,” said Peter Nugent, Senior Scientist and Division Deputy for Science Engagement in the Computational Research Division at Lawrence Berkeley National Laboratory who co-authored the study. “While the spectra bear a resemblance to normal hydrogen-rich core-collapse supernova explosions, they grew brighter and dimmer at least five times more slowly, stretching an event which normally lasts 100 days to over two years.”

Researchers used the Low Resolution Imaging Spectrometer (LRIS) on the Keck I telescope to obtain spectrum of the star’s host galaxy, and the Deep Imaging and Multi-Object Spectrograph (DEIMOS) on Keck II to obtain high-resolution spectra of the unusual star itself.

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