Archive for the ‘asteroids’ Category

Tuesday’s Sunset Treats – 2009April28

Tuesday, April 28th, 2009

Another celestial treat awaits us tonight, as Mercury appears just two degrees from the Pleiades star cluster at sunset.  You’ll find the pair following the sun into your WNW horizon, with Mercury leading the way about eight degrees behind Sol.

Of course, the fun doesn’t stop there.  As the sky darkens, look about six degrees NE of Mercury, for the beautiful V-shaped Hyades – a group totaling about three-hundred stars.  That especially bright orange-tinted star, shining within the left arm of the Hyades’ V, is the red-giant Aldebaran, a coincidental forefront star nearly one-hundred-light years closer than the Hyades cluster.

Our solar system’s brightest asteriod, Vesta, is cruising silently by, about three degrees right of Hyades.  This space rock appears as a seventh-magnitude star, so your best chance at distinguishing it from the background stars is to watch the Hyades region for several nights.  Make note of the star patterns and you’ll soon notice that one star appears to have moved.  You can use this star chart to help you become more familiar with the stars in that region.

Just East of Hyades, you can’t miss the Great Orion Nebula, a bright star-forming region positioned within the “sword” of the constellation Orion.  Spend a little time scanning this entire region with a pair of binoculars.  You’ll be pleasantly surprised.  That bright orange-colored star at Orion’s eastern shoulder is Betelgeuse, a red-giant star similar to Aldebaran but seven times more distant.

Saving the best for last, an opportunity to see four open clusters with the crescent Moon.  Luna is positioned straight up from Hyades and is now almost four-days-old.  Use binoculars to look more closely and you’ll see that the moon is surrounded by stars – M35 is two degrees NE in the constellation Gemini, while M36, M37, and M38 are scattered across a ten-degree region W and S of the moon in the constellation Auriga.

Take some time this evening to go out and enjoy your sunset horizon.  The longer you look, the more you’ll find.  Who knows, maybe you’ll catch sight of a bright meteor or even run across a comet – C/2008 T2 is in Auriga, just three degrees from the Moon.

If you do see anything special, or capture any images, don’t hesitate to share!

Sharing the Sky

Sunday, April 26th, 2009

I am so pleased.  I found a very nice horizon for tonight’s sunset event, and it is in a safe and comfortable location!  It is near the edge of a pretty little pond full of serenading frogs and surrounded by a small field that includes wild rabbits and killdeers.  There are a couple of streetlights in the near vicinity; fortunately, they are a timer that turns them off and on every so often.  I’ll be visiting this special spot often.

Watching tonight’s conjunction was so enjoyable.  The weather was perfect – just enough of a light breeze to keep the mosquitoes away – and the sky was very clear.  The pink and red hues of the sunset were gorgeous, especially when that thin crescent moon suddenly appeared in the still-blue region just above; and then of course, Mercury and Pleiades added perfect sparkle as the sky grew darker.  Several distant airplanes passed through, adding occasional luminous trails to the view.  I even managed to capture one crossing directly in front of the moon.

As I stood there, watching and waiting, I couldn’t help but think of the friends that I’ve made lately and how many of them were probably standing outside their own homes that very moment,  feeling the same way that I do about the night sky.  I thought about the way that those friendships formed across so many miles through one common passion – astronomy – and how those friendships have been my single most valuable resource in my own pursuit of astronomy.  I could read a thousand books, visit a hundred websites, own all the astronomy tools in the world, but without those friendships – that sharing of experiences, knowledge, and excitement – astronomy just would not be the same for me.  I would be just as curious and have that same feeling of wonder, but the pursuit would be almost mechanical and certainly lonely.  Being alone with the stars is one thing – in fact a marvelous thing – but having no one with whom to share that oneness … well, I think it would take the heart and soul right out of astronomy, for me.

This is a meager offering (I wish I were a better photographer) but these pictures of tonight’s conjunction are for my astronomy friends – for all that you give simply by sharing your passion with others, and for allowing me to share with you. (You can click the images for the full-sized versions, and click the x in the bottom-right corner to close.)

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 Luna with Pleiades

Looking at Luna

Friday, April 24th, 2009

This weekend offers two excellent opportunities to observe a very thin crescent moon at sunset.  It’s also a good time to capture some nice “earthshine” images and spot the planet Mercury.

Saturday evening, the new moon will be mere hours old – the thinnest of slivers – with it’s actual age depending upon your location and what time you are observing.  Sunday evening, the moon will be less than two days old – still a thin sliver – and will appear in close position with Pleiades and Mercury.

On both evenings, you’ll find the moon just above your WNW horizon.  On Saturday, Mercury appears above and slightly left of the Moon.  On Sunday,  Mercury appears closer to Luna, this time beneath it, with Pleiades in the middle to form a beautiful trio of objects both near and distant.

Using your binoculars, you can get a good look at that darker portion of the Moon – that region not illuminated by direct sunlight – known as “earthshine.”  We call this ashen-colored region of the Moon “earthshine” because it is the Earth’s own reflected sunlight that makes it visible.  Surprisingly, it was Leonardo Da Vinci, even before  Copernicus’ sun-centered theory, who first described the source of the moon’s illumination, including the secondary glow of earthshine.

Once you’ve browsed the lunar surface, have a look at Mercury.  You might notice a pinkish hue, and this is due to our own atmosphere, just as sunsets and a rising moon sometimes display a red or orange tint.  Of course, you’ll have to focus on Pleiades, as well.  This beautiful cluster is much more distant, but younger than either Mercury or the Moon.  The Pleiades cluster contains about three-thousand member stars, some one-hundred-million years old, and is positioned more than four-hundred light-years away in the constellation Taurus.  Even at that distance, this cluster is actually one of our galaxy’s closest.

Luna currently appears close to the Sun, following it into the horizon at sunset, so you’ll have to keep two things in mind.  One, use special care when observing anywhere near the sun and never ever look directly at the sun through unfiltered binoculars or telescopes.  Two, start your observations before full darkness sets in, else you may find the moon already too low from your location.

For local lunar calculations, I use an excellent program called Quick Phase Pro.  You can also check out the U.S. Naval Observatory for regional lunar information.  Both programs offer lunar rise/set/transit times, phase information, and lunar illumination.  The Quick Phase program offers a few more details, like phase age and historical data.

If you’ve never taken a picture of the moon or evening sky, this is a good time to give it a try.  Any camera should work fine; and remember, it’s not so much how accomplished an image appears, rather, its that you accomplish the effort of imaging.  For better results, take several pictures, changing your settings if your camera allows.

So, get out there this weekend and have a look at Luna; and if you do capture some images, share them with us.  We’d love to see your work.

Turn Down, Reach Out, and Look Up

Sunday, April 19th, 2009

This week, April 20 – April 26, marks International Dark-Sky Week, an organized effort to diminish light pollution and save our night skies.

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For astronomers, the first concern about light pollution is probably its effect on star-gazing.  But studies have shown that the brightening night sky also has measurable negative impacts on human health, animal behavior and populations, the environment, and of course, energy use.

Recent studies suggest a connection between higher cancer rates and lower melatonin concentrations resulting from both greater exposure to nighttime lighting and lessened exposure to natural darkness.

For wildlife, the negative impact of artificial lighting is widespread.  Nocturnal plants and animals are less productive, migrating species become confused, and predator-prey balances are disrupted by distant skyglow, as well as direct lighting.

The economic and environmental impacts of light pollution are self-apparent in higher energy bills and carbon dioxide waste; and much of nighttime lighting, meant to offer safer conditions, is actually hazardous for drivers and pedestrians and inconsiderate to neighbors.

We can all help to darken our night skies by raising awareness about light pollution.  Use this week to learn more and spread the word.  Hand out flyers, host star parties, and contact your local representatives and news media. Most importantly, set the best example yourself.  Utilize proper shades and energy-efficient bulbs on necessary outdoor lighting, and turn off the lights that you really don’t need.

This week, I will tackle light pollution by turning down my own lights, reaching out with information, and of course, encouraging others to look up. I am going to re-access my outdoor lighting, post flyers, contact my local representatives and weekly newspaper, and, weather permitting, host an impromptu star-gazing event.

What will you do to help bring the night sky back?

* Learn more about light pollution and what you can do to help:
Dark Skies Awareness
International Dark-Sky Association
Need-Less
Light Research Center
Windows to the Universe

Near-Earth Object to Pass within 1.2 LD Tonight!

Thursday, March 19th, 2009

I’m a huge fan of imaging near-earth objects, and we have a really “good” one tonight! I’ll be attempting observations (maybe even digital imaging) from my own backyard, as well as ccd imaging through Slooh’s robotic observatory. I just hope that the weather will oblige with clear skies at both locations.

This is a very fast object, making it more discernible for backyard observing but also more challenging for robotic imaging.  Tonight, it will move through four constellations in just five hours – Ursa Major, Draco, Camelopardalis, and Cassiopeia – passing respectably close to several nice galaxies, including M81 and M82, along the way.

You can read more about this object, in my Slooh SkyLog article here; you can get the physical data, including tracking coordinates, here; and you can compare the field of view by entering the coordinates, here.