This Month's Star

This month look for the star Alcyone, the brightest star in the open cluster, the Pleiades. To the Japanese, the cluster is known as Subaru. If you look at the emblem on the same car you’ll see the Pleiades. The Pleiades goes by the name of M-45 and is also known as the Seven Sisters. Most people only see six stars in the Pleiades. The seven sisters were daughters of the titan, Atlas and his wife, Pleione. The six stars most people see, in order of brightness, are named, Alcyone, Electra, Maia, Atlas, Merope, and Taygeta. The next three fainter stars are named after the their mother and the two remaining sisters, Pleione, Celaeno, and Asterope   The first known mention of the Pleiades is by the writer Hesiod around 1000 BC.  

In 10X50 binoculars, the brightest portion of the Pleiades occupies about 1/5th of the field of view. When you include the fainter surrounding stars, the Pleiades occupies closer to 1/4th of the field of view. In moderately light polluted skies, I could easily see 20 stars. In the diagram above, Alcyone, the brightest Pleiad, is the star in the center.

The Pleiades are 369 light years away. So the light you see tonight left the star cluster in the year 1645. There are some 500 stars in this galactic cluster. They formed from the same cloud of dust and gas about 100 million years ago. This means they were born during the middle of the Cretaceous period, or during the hey-day of the dinosaurs. In time the stars of this cluster will drift a part, as their gravity is too weak to hold the cluster together. In other words, there are too few stars spread too far a part. In long duration exposures a blue cloud of dust can be seen surrounding the stars. The stars and bright blue-white frosting makes the Pleiades look like some fantastic piece of jewelry. Contrary to popular belief, this is not the remains of the cloud that the Pleiades formed from. It happens to be a separate cloud that the cluster is currently drifting through. Recent findings have determined that the cloud of dust is actually two separate clouds that are passing each other just as the Pleiades are passing through the same area.  

Transcript for 29 December to 4 January

PAUL
Welcome to Idaho Skies for the first week of January. We’re your hosts, Paul…

RACHEL
… and Rachel.

PAUL
We have two birthdays, an anniversary, and a meteor shower this week.

RACHEL
January 2nd is the birthday of writer Isaac Asimov.

PAUL
Asimov passed away in 1992, but he would have been 94 this year.

RACHEL
Most of our listeners know Asimov for his science and science fiction books.

PAUL
However, he also wrote on many other topics like history and literature.

RACHEL
Did you know he published over 500 books in his lifetime?

PAUL
It helps when you publish your first book at age 19.

RACHEL
The 2nd also marks ten years since the Stardust mission flew past comet Wild 2.

PAUL
Stardust collected samples of comet’s dust as it flew by at a distance of 126 miles.

RACHEL
Then two years later, its reentry capsule returned to Earth in Utah, bringing those samples back for analysis.

PAUL
Although we spell the comet’s name like the word wild, it’s actually the name of the German astronomer who discovered it.

RACHEL
The two comes from the fact that this was his second comet discovery.

PAUL
In the world of professional astronomy, the discoverer of a new comet has the privilege of naming the comet after him or her.

RACHEL
The first astronomer to have this honor was Edmund Halley.

PAUL
Halley didn’t actually discover this comet; people had observed it for over 1,000 years.

RACHEL
One example is the Bayeux Tapestry, where the comet’s image adds a sense of foreboding for the king of England, Harold.

PAUL
We name the comet after Halley because he was the first to determine that many of the comet’s observed over history were actually the same comet returning every 76 years.

RACHEL
He also predicted when it would make its next appearance.

PAUL
Edmund Halley never lived to see his predicted comet return, however, since he nailed its return, we name the comet after him.

RACHEL
Halley predicted the return of his comet because he was a friend and firm believer in Isaac Newton.

PAUL
Newton also celebrates this birthday this week.

RACHEL
On the 4th as a matter of fact.

PAUL
Our astronomical event for this week is the Quadrantid meteor shower.

RACHEL
It’s a nice shower that peaks on the night of the 3rd and morning of the 4th.

PAUL
Quadrantid meteors will appear to radiate from low in the northeast, at a point just below the bowl of the Big Dipper.

RACHEL
The shower is best observed after midnight.

PAUL
You can expect to see 45 meteors per hour from this shower.

RACHEL
However, most of them won’t be bright, so watch from a dark location.

PAUL
The best way to watch this shower is to lie back on a lawn chair and look straight up.

RACHEL
Be sure to take a warm sleeping bag with you.

PAUL
And hot drinks are also helpful.

RACHEL
That’s Idaho Skies for the first week of January. Next week Earth reaches perihelion and we celebrate the discovery of Jupiter’s satellites.

PAUL
Be sure to follow us on Twitter at Idaho Skies for this week’s event reminders and sky maps.

For Idaho Skies this is Paul…

RACHEL
and Rachel.

PAUL
Dark skies and bright stars.

Transcript for December 22 - 28

RACHEL
Welcome to Idaho Skies for the last week of December. We’re your hosts, Rachel...

PAUL
...and Paul.

RACHEL
December’s second meteor shower peaks on the 22nd.

PAUL
Meteors from the Ursid meteor shower appear to originate from the north and are at their best before the moon rises at 10:00 PM.

RACHEL
You can expect to see about a dozen faint meteors per hour from this shower.

PAUL
However, it has surprised astronomers with significantly higher rates on occasion.

RACHEL
When the moon rises on the morning of the 25th, look for a slightly orangish star to its left.

PAUL
That’s Mars.

RACHEL
Unfortunately, this is not a good time to view Mars through a telescope as it’s too far away and too small in diameter to show any detail.

PAUL
Every two years this changes however, so be patient.

RACHEL
The moon is last quarter on the 25th.

PAUL
So if you got a new telescope for Christmas, you can test it on the moon.

RACHEL
That is if you can wait until it rises after 2:00 AM on the 26th.

PAUL
Want to try out your new telescope on Saturn?

RACHEL
You can easily find Saturn on the morning of the 28th if you find the crescent moon first.

PAUL
It’s located in the low east.

RACHEL
At 6:00 AM, Saturn is the creamy-yellow star to the moon’s lower left.

PAUL
You will need a magnification of at least 25 times to see its rings.

RACHEL
But less magnification is required to see its largest satellite, Titan.

PAUL
Titan will appear star-like in your telescope

RACHEL
And it’s to Saturn’s upper right.

PAUL
Much closer to the moon is a star named Zubenelgenubi.

RACHEL
This star is a wide double star and it’s easy to split into two stars through binoculars.

PAUL
A thin crescent moon, just two days from new, appears in the morning sky on the 30th.

RACHEL
To see it, use binoculars and begin sweeping the low southeast at 6:45 AM.

PAUL
The moon will be less than a binocular’s field of view above the horizon.

RACHEL
But you’ll need to work quickly though.

PAUL
That’s because by 7:15 AM, the sky will begin brightening enough to make it difficult to see the moon.

RACHEL
Looking any later is dangerous too because you might sweep up the sun in your binoculars.

FADE IN MUSIC

PAUL
That’s Idaho Skies for the last week of December. Join us next month for the space and astronomy events for Idaho.

RACHEL
Be sure to read our blog for additional information. It’s at idahoskies.blogspot.com For Idaho Skies this is Rachel...

PAUL
and Paul.

RACHEL
Dark skies and bright stars.

Meteor Presentation

The Street Astronomer gave a presentation on meteors last week at Deer Flat NWR. The presentation is now online at SlideShare.

http://www.slideshare.net/NearSys/meteor-showers-29232037

Transcript for December 15 to 21

PAUL
Welcome to Idaho Skies for the third week of December. We’re your hosts, Paul...

RACHEL
...and Rachel.

PAUL
On the evening of the 15th, the moon is next to the Hyades star cluster.

RACHEL
The Hyades is the large star cluster that forms the face of Taurus the Bull.

PAUL
Because of the size of the Hyades, this is an event for your binoculars and not a telescope.

RACHEL
The moon is full on the night of the 17th.

PAUL
Also, there are two important historical events on the 17th that helped create today’s space and astronomy world.

RACHEL
We begin with the first heavier than air flight.

PAUL
One hundred and ten years ago, Orville and Wilbur Wright flew their airplane, the Wright Flyer for 12 seconds.

RACHEL
The flight took place at a sand dune named Big Kill Devil Hill and the airplane only flew 120 feet.

PAUL
Even though the flight was shorter than the wing span of a Boeing 747, it ushered in the age of flight.

RACHEL
Today astronomers use airplanes to carry astronomical telescopes high above water vapor in the air.

PAUL
Airplanes are also being used to replace the first stage of rockets.

RACHEL
Fifty-five years ago in 1958, NASA created Project Mercury.

PAUL
Project Mercury had three basic goals.

RACHEL
First was to place an astronaut in orbit around Earth.

PAUL
Second was to observe how an astronaut performed in the weightlessness of space.

RACHEL
Third was to recover the astronaut and spacecraft safely in one piece after the mission.

PAUL
There were a total of six manned Mercury missions between 1961 and 1963.

RACHEL
Jupiter is the bright star to the moon’s upper left on the 18th.

PAUL
If you prop your binoculars on something steady, you may be able to make out all four of its Galilean Satellites.

RACHEL
A small telescope definitely will show them.

PAUL
In binoculars, you will see from lower left to upper right, the satellites are Ganymede, then Jupiter, followed by Io, Europa, and Callisto.

RACHEL
A telescope reverses this order.

PAUL
Io, Europa, and Callisto are close enough together that it may be difficult to cleanly separate them in your binoculars - steadiness is beneficial.

RACHEL
The moon passes very close to the M-67 star cluster on the evening of the 20th.

PAUL
Use binoculars and scan an area just to the moon’s upper right.

RACHEL
The cluster appears more impressive if you shift the binoculars to take the moon out of the field of view.

PAUL
Winter begins on December 21st at 10:11 AM.

RACHEL
At that time, Earth’s South Pole is facing directly towards the sun.

PAUL
This results in 24 hours of darkness for anyone living north of the Arctic Circle.

RACHEL
It is also the Northern Hemisphere’s shortest day.

PAUL
From now until summer, the days will begin growing longer and the nights shorter.

PAUL
That’s Idaho Skies for the third week of December. Next week is Christmas and we’ll give you a few targets for that new telescope.

RACHEL
Be sure to follow us on Twitter at Idaho Skies for this week’s event reminders and sky maps.

For Idaho Skies this is Rachel...

PAUL
and Paul.

RACHEL
Dark skies and bright stars.

Transcript for December 8-15

RACHEL
Welcome to Idaho Skies for the second week of December. We’re your hosts, Rachel...

PAUL
...and Paul.

RACHEL
The moon is at first quarter on the 9th.

PAUL
The quarter moon is among the best times to look at the moon through your binoculars or small telescope.

RACHEL
Concentrate your efforts along the straight-line boundary between day and night, or what astronomers call the terminator.

PAUL
The terminator is where shadows cast by the rising sun stretch their longest length.

RACHEL
Since the terminator directly faces Earth at first quarter, the moon’s curvature doesn’t foreshorten the shadows.

PAUL
The combination of long shadows and no apparent foreshortening lets the terminator accentuate the smallest lunar surface features.

RACHEL
The Geminid meteor shower peaks on the night of the 13th and morning of the 14th.

PAUL
The moon is full in another three days, so in order to have your best views of this shower you’ll want to go outside after the moon sets at 4:00 AM.

RACHEL
Even though this is early for meteor watching, this shower is still worth your time.

PAUL
That’s because at its peak, 80 meteors per hour are visible from this shower.

RACHEL
In addition, the meteors are relatively bright and easy to see.

PAUL
Did you know that Geminid meteors appear yellowish in color rather than white like most meteors?

RACHEL
Something else that makes the Geminids unique is that their parent is an asteroid rather than a comet.

PAUL
This means the typical Geminid meteoroid is rocky and not fluffy comet dust.

RACHEL
You’ll know a meteor is a Geminid if it appears to radiate from a point high in the west-southwest.

PAUL
On the 14th, the moon is well placed between two large and bright star clusters.

RACHEL
The star clusters are the Pleiades and Hyades.

PAUL
This is an another great opportunity to use your binoculars.

RACHEL
That’s because the typical telescope has too much magnification.

PAUL
If you have a digital camera, tripod, and cable release, you might try taking a picture of this grouping.

RACHEL
The exposure time only needs to be a few seconds long.

PAUL
So using a tripod and cable release is important to keep the camera motionless during the exposure.

RACHEL
That’s Idaho Skies for the second week of December. The moon leads us to Jupiter next week and we’ll tell you how to see its largest moons through your binoculars.

PAUL
Be sure to read our blog for additional information. It’s at idahoskies.blogspot.com. For Idaho Skies this is Paul...

RACHEL
and Rachel.

PAUL
Dark skies and bright stars.