RACHEL
Welcome to Idaho Skies for May 20th and 21st. We’re your hosts, Rachel…
PAUL
…and Paul.
RACHEL
Today we celebrate astronomer Williamina Fleming.
PAUL
She was born in Scotland on May 15th, 1857 and died in the United States on May 21st, 1911. She started working as a maid at the Harvard Observatory at age 21. The observatory’s director later assigned her to clerical work and then finally as a computer. In the late 19th century, computers were people, usually women, who performed mathematical calculations for scientists.
RACHEL
Astronomers at the time were trying to create a classification scheme for stars. There isn’t enough information in just the color of a star, but there is if you split its colors up with a spectroscope. So astronomers spent minutes and even hours photographing stars though a spectroscope.
PAUL
The lines appearing in a star’s spectrum indicates the elements in its outer atmosphere. There’s also information on the star’s surface temperature buried within its spectra. However, astronomers needed a meaningful way to classify these spectra. And Ms. Fleming determined to way to do this based on the amount of hydrogen displayed in each star’s spectra.
RACHEL
Willimina also famous to discovering a very faint star that was intensely hot. Hot stars tend to be bright stars. Since it wasn’t bright, the star had to be very small. On the order of planet small. These dense white-hot stars were eventually named white dwarfs and they represent the end of life for low mass stars like the sun.
PAUL
That’s Idaho Skies for the 20th and 21st of May.
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.
Monday, May 20, 2019
Tuesday, May 14, 2019
Potential Auroras
Sunspot AR2741 is an active site on the sun. It's hurled a coronal mass ejection (CME) our way that could result in Idaho seeing the Northern Lights. so be on the look out Wednesday and Thursday nights.
Monday, May 13, 2019
Sunspot AR2741
Sunspot AR2741 is larger than Earth. In this image, you can see the darker umbra and that it's surrounded by a lighter penumbra.
Sunday, May 12, 2019
Idaho Skies Transcript for May 17th, 18th, and 19th
PAUL
Welcome to Idaho Skies for May 17th, 18th, and 19th. We’re your hosts, Paul...
RACHEL
...and Rachel.
BRING DOWN MUSIC
PAUL
On our last show, we mentioned that there was a cluster of galaxies residing in Virgo.
RACHEL
Galaxy clusters consist of hundreds to over a thousand galaxies bound together by their mutual gravity. The combined mass of all the stars inside a galaxy cluster can equal one quadrillion times the mass of our sun. From one end to the other, they can stretch tens of millions of light years across.
PAUL
Greater than the mass of all the stars in all the galaxies of a galaxy cluster is the gas trapped between them. Galaxy clusters have almost ten times as much gas than stars. Massive black holes inside the centers of the galaxies heat the gas until it emits x-rays.
RACHEL
Did you know that galaxy clusters are not the largest structures in the universe? Galaxy clusters combine with others to create superclusters. Let’s start with our puny little Milky Way galaxy. It’s only 100,000 light years across. It belongs to the Local Group of 54 galaxies, including the Andromeda Galaxy.
PAUL
Our Local Group is an outlying member of the Virgo Cluster. The Virgo Cluster on the other hand is just but a part of the Laniakea Supercluster. Our Local Group of 54 galaxies only spans 2% of the Laniakea Supercluster’s 500 million light year diameter. Astronomers estimate that there are 100,000 galaxies in the Laniakea Supercluster.
RACHEL
That’s Idaho Skies for the 17th, 18th, and 19th of May.
PAUL
Be sure to follow us on Twitter @IdahoSkies for this week’s event reminders and sky maps.
For Idaho Skies this is Paul...
RACHEL
...and Rachel.
RACHEL
Dark skies and bright stars.
Welcome to Idaho Skies for May 17th, 18th, and 19th. We’re your hosts, Paul...
RACHEL
...and Rachel.
BRING DOWN MUSIC
PAUL
On our last show, we mentioned that there was a cluster of galaxies residing in Virgo.
RACHEL
Galaxy clusters consist of hundreds to over a thousand galaxies bound together by their mutual gravity. The combined mass of all the stars inside a galaxy cluster can equal one quadrillion times the mass of our sun. From one end to the other, they can stretch tens of millions of light years across.
PAUL
Greater than the mass of all the stars in all the galaxies of a galaxy cluster is the gas trapped between them. Galaxy clusters have almost ten times as much gas than stars. Massive black holes inside the centers of the galaxies heat the gas until it emits x-rays.
RACHEL
Did you know that galaxy clusters are not the largest structures in the universe? Galaxy clusters combine with others to create superclusters. Let’s start with our puny little Milky Way galaxy. It’s only 100,000 light years across. It belongs to the Local Group of 54 galaxies, including the Andromeda Galaxy.
PAUL
Our Local Group is an outlying member of the Virgo Cluster. The Virgo Cluster on the other hand is just but a part of the Laniakea Supercluster. Our Local Group of 54 galaxies only spans 2% of the Laniakea Supercluster’s 500 million light year diameter. Astronomers estimate that there are 100,000 galaxies in the Laniakea Supercluster.
RACHEL
That’s Idaho Skies for the 17th, 18th, and 19th of May.
PAUL
Be sure to follow us on Twitter @IdahoSkies for this week’s event reminders and sky maps.
For Idaho Skies this is Paul...
RACHEL
...and Rachel.
RACHEL
Dark skies and bright stars.
Idaho Skies Transcript for May 15th and 16th
RACHEL
Welcome to Idaho Skies for May 15th and 16th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
The evening sky during spring is devoid of bright stars.
PAUL
In fact, the only event this week involving the moon and bright stars occurs on the 15th when the gibbous moon appears above Spica. Spica is the brightest star of Virgo the Maiden. The star is a giant binary star 250 light years away. To be visible that far away, it must be 20,000 times brighter than the sun.
RACHEL
The mythology of Virgo associates her as a goddess of either harvest or of justice. So it’s not surprising that her brightest star, Spica is named after an ear of grain. And as a goddess of justice, it’s not surprising that her neighboring constellation is Libra the Scales.
PAUL
Our listeners won’t see very many stars surrounding Spica. Although Virgo is a large constellation, it’s filled with widely-spaced dim stars. The reason why this region of the sky is so blank is that points up through the North Pole of the Milky Way galaxy. That means we’re looking though less galactic volume during spring nights.
RACHEL
On the other hand, with fewer stars comes less obscuring gas and dust. As a result, astronomers can see more galaxies in this region of the sky. For example, the Virgo Cluster is a gravitationally-bound cluster of over 1,000 galaxies. Its center lies 53 million light years away.
PAUL
That’s Idaho Skies for the 15th and 16th of May.
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.
Welcome to Idaho Skies for May 15th and 16th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
The evening sky during spring is devoid of bright stars.
PAUL
In fact, the only event this week involving the moon and bright stars occurs on the 15th when the gibbous moon appears above Spica. Spica is the brightest star of Virgo the Maiden. The star is a giant binary star 250 light years away. To be visible that far away, it must be 20,000 times brighter than the sun.
RACHEL
The mythology of Virgo associates her as a goddess of either harvest or of justice. So it’s not surprising that her brightest star, Spica is named after an ear of grain. And as a goddess of justice, it’s not surprising that her neighboring constellation is Libra the Scales.
PAUL
Our listeners won’t see very many stars surrounding Spica. Although Virgo is a large constellation, it’s filled with widely-spaced dim stars. The reason why this region of the sky is so blank is that points up through the North Pole of the Milky Way galaxy. That means we’re looking though less galactic volume during spring nights.
RACHEL
On the other hand, with fewer stars comes less obscuring gas and dust. As a result, astronomers can see more galaxies in this region of the sky. For example, the Virgo Cluster is a gravitationally-bound cluster of over 1,000 galaxies. Its center lies 53 million light years away.
PAUL
That’s Idaho Skies for the 15th and 16th of May.
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.
Idaho Skies Transcript for May 13th and 14th
PAUL
Welcome to Idaho Skies for May 13th and 14th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
Earth’s orbit around the sun makes the sun appear to travel through 13 constellations. We call 12 of these the zodiac.
RACHEL
Zodiac has the same root word found in zoo. So listeners won’t be surprised that the word zodiac is from the Greek for circle of little animals. All but one of the zodiacal constellations are animals in one form or another. The one constellation that is not an animal is Libra the Scales. However, it used to be a part of Scorpius.
PAUL
Three of the constellations represent humans. Those are Gemini, Virgo, and Aquarius. Six are strictly animals, Aries the Ram, Taurus the Bull, Cancer the Crab, Leo the Lion, Scorpius the Scorpion, and Pisces the Fish. The remaining two are chimeras or mixtures of animals. These are Sagittarius the Centaur Archer and Capricornus, the half goat half fish.
RACHEL
Technically, there’s nothing special about these constellations. If Earth’s orbit was tilted at a different angle, then the sun would appear to travel through a different set of constellations. Besides, the constellations and their boundaries are human inventions and not special to the universe overall.
PAUL
Because Earth’ spin axis wobbles every 26,000 years, the actual zodiacal constellation the sun occupies each day shifts. About 2,000 years ago, the sun resided in Cancer on the first day of summer. This is why we call the latitude of 23.5 degrees north the Tropic of Cancer. The latitude of 23.5 degrees south is called the Tropic of Capricorn for the opposite reason.
RACHEL
That’s Idaho Skies for the 13th and 14th of May.
PAUL
Be sure to follow us on Twitter @IdahoSkies for this week’s event reminders and sky maps.
For Idaho Skies this is Paul...
RACHEL
...and Rachel.
PAUL
Dark skies and bright stars.
Welcome to Idaho Skies for May 13th and 14th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
Earth’s orbit around the sun makes the sun appear to travel through 13 constellations. We call 12 of these the zodiac.
RACHEL
Zodiac has the same root word found in zoo. So listeners won’t be surprised that the word zodiac is from the Greek for circle of little animals. All but one of the zodiacal constellations are animals in one form or another. The one constellation that is not an animal is Libra the Scales. However, it used to be a part of Scorpius.
PAUL
Three of the constellations represent humans. Those are Gemini, Virgo, and Aquarius. Six are strictly animals, Aries the Ram, Taurus the Bull, Cancer the Crab, Leo the Lion, Scorpius the Scorpion, and Pisces the Fish. The remaining two are chimeras or mixtures of animals. These are Sagittarius the Centaur Archer and Capricornus, the half goat half fish.
RACHEL
Technically, there’s nothing special about these constellations. If Earth’s orbit was tilted at a different angle, then the sun would appear to travel through a different set of constellations. Besides, the constellations and their boundaries are human inventions and not special to the universe overall.
PAUL
Because Earth’ spin axis wobbles every 26,000 years, the actual zodiacal constellation the sun occupies each day shifts. About 2,000 years ago, the sun resided in Cancer on the first day of summer. This is why we call the latitude of 23.5 degrees north the Tropic of Cancer. The latitude of 23.5 degrees south is called the Tropic of Capricorn for the opposite reason.
RACHEL
That’s Idaho Skies for the 13th and 14th of May.
PAUL
Be sure to follow us on Twitter @IdahoSkies for this week’s event reminders and sky maps.
For Idaho Skies this is Paul...
RACHEL
...and Rachel.
PAUL
Dark skies and bright stars.
Tuesday, May 7, 2019
Sunspot AR2740 and AR2741
Sunspot AR2740 used to be called AR2738 before it rotated to the far side of the sun. The sun rotates once every 27 or so days (the number of days is different for different latitudes). Since AR2738 survived for more than 14 days, the sun's rotation brought it back to our view again. As a result, astronomers gave it a new name, AR2740.
The image below shows the sunspot taken with a cellphone through a safe solar telescope. If you look carefully to the spot's lower left, there's another sunspot very close to the sun's edge. In a another few days, this spot ought to be easily visible. The spot's name is AR2741.
The sun is in a quiet phase, so it's a pleasant surprise to see sunspots at this time.
The image below shows the sunspot taken with a cellphone through a safe solar telescope. If you look carefully to the spot's lower left, there's another sunspot very close to the sun's edge. In a another few days, this spot ought to be easily visible. The spot's name is AR2741.
The sun is in a quiet phase, so it's a pleasant surprise to see sunspots at this time.
Monday, May 6, 2019
Idaho Skies Transcript for May 10th, 11th, and 12th
RACHEL
Welcome to Idaho Skies for May 10th, 11th, and 12th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
While listeners relax this weekend, the moon will be very busy on astronomical business.
PAUL
Have your binoculars ready as soon as it gets dark on the 10th. Stargazers will find the half full moon a mere one degree away for the Beehive Star cluster. Recall that binoculars have a field of view of 7.5 degrees and the moon appears half a degree across. So the Beehive will appear in binoculars with the moon and only two lunar diameters away.
RACHEL
The Beehive will appear as a sprinkle of stars to the moon’s right. Since the moon’s light will interfere, you won’t see the two dozen or more stars people can normally see. However, you will notice the star cluster appears as large as the moon. The star cluster has over 1,000 stars and is around 600 light years away.
PAUL
The moon then reaches first quarter on the 12th. So this weekend will be a perfect time to observe the moon through binoculars, spotting scope, or small telescope. With the terminator turned directly towards Earth, the straight edge between day and night will appear flush with craters.
RACHEL
Before turning in for the night on Sunday, take a moment to stargaze. You’ll find the moon located at the base of Leo the Lion. The star located to the moon’s lower right is Regulus, the Lion’s heart. The star farther away to the moon’s upper left is called Denebola. This is the base of the Lion’s tail.
PAUL
That’s Idaho Skies for the 10th, 11th, and 12th of May.
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.
Welcome to Idaho Skies for May 10th, 11th, and 12th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
While listeners relax this weekend, the moon will be very busy on astronomical business.
PAUL
Have your binoculars ready as soon as it gets dark on the 10th. Stargazers will find the half full moon a mere one degree away for the Beehive Star cluster. Recall that binoculars have a field of view of 7.5 degrees and the moon appears half a degree across. So the Beehive will appear in binoculars with the moon and only two lunar diameters away.
RACHEL
The Beehive will appear as a sprinkle of stars to the moon’s right. Since the moon’s light will interfere, you won’t see the two dozen or more stars people can normally see. However, you will notice the star cluster appears as large as the moon. The star cluster has over 1,000 stars and is around 600 light years away.
PAUL
The moon then reaches first quarter on the 12th. So this weekend will be a perfect time to observe the moon through binoculars, spotting scope, or small telescope. With the terminator turned directly towards Earth, the straight edge between day and night will appear flush with craters.
RACHEL
Before turning in for the night on Sunday, take a moment to stargaze. You’ll find the moon located at the base of Leo the Lion. The star located to the moon’s lower right is Regulus, the Lion’s heart. The star farther away to the moon’s upper left is called Denebola. This is the base of the Lion’s tail.
PAUL
That’s Idaho Skies for the 10th, 11th, and 12th of May.
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.
Idaho Skies Transcript for May 8th and 9th
PAUL
Welcome to Idaho Skies for May 8th and 9th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
On the 8th and 9th, the moon passes through Gemini the Twins.
RACHEL
Gemini is one of the original 48 constellations listed by Ptolemy back in second century AD. In mythology, Gemini represents the twin brothers, Castor and Pollux. Their mother was Leda, the queen of Sparta. Her twin sons had two fathers, her husband Tyndareus and the Greek god Zeus.
PAUL
Castor was the mortal brother while Pollux was immortal. The brothers are famous for being sailors on Jason’s voyage to find the Golden Fleece. Their presence onboard the Argo helped calm the sea during a rough patch of their journey. Since then, sailors have considered the Gemini Twins to be their protectors.
RACHEL
Gemini is one of the12 constellations of the Zodiac. This means the constellation lies along the elliptic and that sun, moon, and planets can appear within it. Its brightest two stars are named Castor and Pollux, with Pollux being the slight brighter one. One of the best meteor showers appears in Gemini and peaks on the night of December 13th and 14th.
PAUL
Castor appears as a single star to our eyes and as three stars through a small telescope. It turns out that astronomers using a spectroscope can detect that each of those stars is actually two in orbit around each other. Pollux on the other hand is just a single star. But a giant yellow-orange star nine times larger than our sun.
RACHEL
That’s Idaho Skies for the 8th and 9th of May.
PAUL
Be sure to follow us on Twitter @IdahoSkies for this week’s event reminders and sky maps.
For Idaho Skies this is Paul...
RACHEL
...and Rachel.
PAUL
Dark skies and bright stars.
Welcome to Idaho Skies for May 8th and 9th. We’re your hosts, Paul...
RACHEL
...and Rachel.
PAUL
On the 8th and 9th, the moon passes through Gemini the Twins.
RACHEL
Gemini is one of the original 48 constellations listed by Ptolemy back in second century AD. In mythology, Gemini represents the twin brothers, Castor and Pollux. Their mother was Leda, the queen of Sparta. Her twin sons had two fathers, her husband Tyndareus and the Greek god Zeus.
PAUL
Castor was the mortal brother while Pollux was immortal. The brothers are famous for being sailors on Jason’s voyage to find the Golden Fleece. Their presence onboard the Argo helped calm the sea during a rough patch of their journey. Since then, sailors have considered the Gemini Twins to be their protectors.
RACHEL
Gemini is one of the12 constellations of the Zodiac. This means the constellation lies along the elliptic and that sun, moon, and planets can appear within it. Its brightest two stars are named Castor and Pollux, with Pollux being the slight brighter one. One of the best meteor showers appears in Gemini and peaks on the night of December 13th and 14th.
PAUL
Castor appears as a single star to our eyes and as three stars through a small telescope. It turns out that astronomers using a spectroscope can detect that each of those stars is actually two in orbit around each other. Pollux on the other hand is just a single star. But a giant yellow-orange star nine times larger than our sun.
RACHEL
That’s Idaho Skies for the 8th and 9th of May.
PAUL
Be sure to follow us on Twitter @IdahoSkies for this week’s event reminders and sky maps.
For Idaho Skies this is Paul...
RACHEL
...and Rachel.
PAUL
Dark skies and bright stars.
Idaho Skies Transcript for May 6th and 7th
RACHEL
Welcome to Idaho Skies for May 6th and 7th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
It is a busy next few days; we have a meteor shower and several astronomical pairings to enjoy.
PAUL
First, the Eta Aquarid meteor shower is not over yet. The moon is only two days old on Monday. This means its light won’t interfere with the shower. Just look for streaks of light originating from the low southeast. Your chance of seeing meteors improves after midnight.
RACHEL
Then on the 6th, the two-day old crescent moon appears just below Aldebaran. Aldebaran is the brightest star in Taurus the Bull and the pair of them will appear in the low west-northwest. Look for a faintly yellowish star and then the moon just above it. Your binoculars will be perfect for this event.
PAUL
Mars is approaching ever closer to the sun this spring. As it does, it gets farther away from Earth and fainter. This might make it difficult to identify from the background stars. However, there’s some help on the 7th. That evening, the waxing crescent moon appears four degrees away from the Red Planet. Mars will be the yellowish star to the moon’s right.
RACHEL
Finally, be sure to get your binoculars out on the 7th. While they won’t show you any details on Mars, they will let you see a star cluster. The star cluster’s name is M-35 and it’s just above the moon. Place the moon at the bottom of your binocular view and then look for a small sprinkle of stars at the top.
PAUL
That’s Idaho Skies for the 6th and 7th of May.
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.
Welcome to Idaho Skies for May 6th and 7th. We’re your hosts, Rachel...
PAUL
...and Paul.
RACHEL
It is a busy next few days; we have a meteor shower and several astronomical pairings to enjoy.
PAUL
First, the Eta Aquarid meteor shower is not over yet. The moon is only two days old on Monday. This means its light won’t interfere with the shower. Just look for streaks of light originating from the low southeast. Your chance of seeing meteors improves after midnight.
RACHEL
Then on the 6th, the two-day old crescent moon appears just below Aldebaran. Aldebaran is the brightest star in Taurus the Bull and the pair of them will appear in the low west-northwest. Look for a faintly yellowish star and then the moon just above it. Your binoculars will be perfect for this event.
PAUL
Mars is approaching ever closer to the sun this spring. As it does, it gets farther away from Earth and fainter. This might make it difficult to identify from the background stars. However, there’s some help on the 7th. That evening, the waxing crescent moon appears four degrees away from the Red Planet. Mars will be the yellowish star to the moon’s right.
RACHEL
Finally, be sure to get your binoculars out on the 7th. While they won’t show you any details on Mars, they will let you see a star cluster. The star cluster’s name is M-35 and it’s just above the moon. Place the moon at the bottom of your binocular view and then look for a small sprinkle of stars at the top.
PAUL
That’s Idaho Skies for the 6th and 7th of May.
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.
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