Daily Archives: April 9, 2014

astronomy

There’s a Red Moon on the Rise

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Get Ready for the April 14-15 Total Lunar Eclipse

On Monday April 14th, late in the evening for most folks in the U.S., the Moon will pass through Earth’s shadow. That event, called a total lunar eclipse, will begin just before 4:55 a.m. UTC on April 15th, (that’s 12:55 a.m., EDT, 11:55 p.m. CDT, 10:55 p.m. MDT, and 9:55 p.m. PDT on April 14th) and last for several hours before it passes out of the shadow. Sure, it’s early in the morning for most of us, but you don’t get to see these things very often, so I advise you make some plans to stay up late (maybe after you’ve made that last mad dash to the Post Office to mail your taxes (if you’re in the U.S.) and watch the show. To help you along, the folks at the Slooh.com will be hosting a five-hour event, starting with coverage of Mars, starting at 7 p.m. PDT. They’ll focus their telescopes on the Red Planet, and then the eclipse. Along the way, you’ll hear from astronomy experts, giving their view on the events occurring the sky.

A Stellarium view of the April 14-15 total lunar eclipse. (Stellarium.com)
A Stellarium view of the April 14-15 total lunar eclipse during the darkest part when the Moon is in the umbral part of Earth’s shadow. (Stellarium.com)

If you do take the opportunity to see the eclipse, here’s what you can expect. First, as the Moon slips into the penumbra (the outer shadow), it will start to get slightly dark. In all fairness, it will be fairly difficult to tell the Moon is darkening during this phase, unless you have a light meter and can measure the changing albedo of the Moon. However, once it slips into the umbra (the full Earth shadow) at 12:08 a.m. PDT (3:08 a.m. EDT), the Moon will be noticeably darker, and begin to take on a coppery-red color. It appears not too far from the bright shiny star Spica, with Red Mars not too far away, and brilliant Saturn at lower left.

Eventually the Moon leaves the umbra at 1:23 a.m. PDT (5:23 a.m. EDT), moving back into the penumbra, and the eclipse ends at 3:36 a.m. PDT (6:36 a.m. EDT).

People all over the Americas will be able to see this eclipse, along with folks in parts of the Pacific (see a complete list here) will be able to glimpse some or all of it.

I’ve witnessed I don’t know how many lunar eclipses and have seen four total solar eclipses and one annular. Each one is special, and different. Each one brings with it a sense of awe, and teaches us just how cool it is that our Earth orbits the Sun, our Moon orbits Earth, and sometimes they all line up in just the right way in a perfectly normal occurrence that happens over and over again.

Give yourself the gift of a lunar eclipse next week. Start planning now to watch as Earth’s shadow slips across the face of the Moon. For more information on the eclipse, visit MrEclipse.comand Timeanddate.com. And, if the weather’s poor at your location, or you’re in an area where the eclipse can’t be seen at all, be sure and check out the Slooh.com webcast.

astronomy

A Diamond Ring For a Dying Star

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Planetary Nebula Abell 33 — A Star In Its Death Throes

Astronomers using ESO’s Very Large Telescope in Chile have captured this eye-catching image of planetary nebula Abell 33. Created when an aging star blew off its outer layers, this beautiful blue bubble is, by chance, aligned with a foreground star, and bears an uncanny resemblance to a diamond engagement ring. This cosmic gem is unusually symmetric, appearing to be almost perfectly circular on the sky. Credit: ESO
This eye-catching image of planetary nebula Abell 33 bears an uncanny resemblance to a diamond ring. This cosmic gem is unusually symmetric, appearing to be almost perfectly circular on the sky.
Credit: ESO

Wow!  I’ve seen some gorgeous astro-images, but this one is just so evocative! This is what it looks like when a star about like our Sun blows off its outer layers as it ages. It becomes a planetary nebula, so named by astronomer Sir William Herschel because these dim little wisps of light looked like what he thought newborn planetary systems looked like through his low power (by today’s standards) telescope.

In this case, the star has expelled its top layers to space and the material has expanded to form a gorgeous blueish balloon of material. The edge of the bubble just happens to be aligned with a nearby star, and the combo of light and glowing stellar material is just gorgeous.

Astronomers using the European Southern Observatory’s Very Large Telescope in Chile captured this sight using data from the FORS Spectrograph attached to the Very Large Telescope.  The scene it witnessed is a familiar one to those who study the lives and deaths of sun-like stars.

Most stars with masses similar to that of our Sun will end their lives like this. First, they blow off their atmospheres, which creates glowing and often colorful clouds called planetary nebulae. In this case, the cloud is surrounding what’s left of the progenitor star (the one that’s dying) is just slightly off-center in the image. It’s shrinking as it ages, and will end its days as a white dwarf. It looks dim here, but actually, the aging star is much more luminous than the Sun. It’s giving off tremendous amounts of ultraviolet radiation, which is causing the bubble of material to glow.

This particular planetary nebula, called Abell 33, lies some 2,500 light-years from Earth. Its perfectly round shape is somewhat unusual. Oftentimes there is more than one star involved in one of these stellar death scenes. Sometimes it’s one star of a binary pair that starts to die — and that affects the shape of the resulting planetary nebula.

This is one of the reasons I love astronomy. Just when you think you’ve seen it all, the universe tosses another gorgeous vision your way.