Moon occults ex-pole star January 19

The moon was to the west of Aldebaran yesterday, on January 18.

Tonight – January 19, 2016 – the waxing gibbous moon passes in front of – or occults – Aldebaran, an ex-pole star and the brightest star in the constellation Taurus the Bull. So that’s why Aldebaran is missing from the above sky chart – because we’re depicting it with the moon is covering it. For an idea of Aldebaran’s whereabouts, check the chart at right for the day before, on January 18.

From much of North America, the moon will occult – cover over – Aldebaran for an hour or so during the nighttime hours on this date. Aldebaran will disappear behind the moon’s dark side and reappear on its illuminated side. We give the local occultation times for four US cities:

New York, NY Eastern Standard Time (EST)
Occultation begins: 9:31 p.m. EST
Occultation ends: 10:43 p.m. EST

Kansas City, MO Central Standard Time (CST)
Occultation begins: 7:47 p.m. CST
Occultation ends: 9:03 p.m. CST

Denver, CO Mountain Standard Time (MST)
Occultation begins: 6:29 p.m. MST
Occultation ends: 7:46 p.m. MST

Los Angeles, CA Pacific Standard Time (PST)
Occultation begins: 5:03 p.m. PST
Occultation ends: 6:14 p.m. PST

View larger Occultation map via IOTA (International Occultation Timing Organization). All places within the solid white lines can see the occultation of Aldebaran sometime during the nighttime hours on January 19-20, 2016.

Click here to find out the occultation times for your locality in Universal Time (UT). To convert Universal Time (UT) to your local time:

Atlantic Standard Time = UT – 4 hours
Eastern Standard Time = UT – 5 hours
Central Standard Time = UT – 6 hours
Mountain Standard Time = UT – 7 hours
Pacific Standard Time = UT – 8 hours.

Occultation of Aldebaran on January 19-20

Aldebaran, the ex-pole star

Although Aldebaran now reigns as a star of the Zodiac, did you know that Aldebaran is a former pole star?

It’s true, and it’s a fascinating story.

Many people know that Polaris is the present-day North Star, but few know that Aldebaran reigned as the North Star some 450,000 years ago.

What’s more, Aldebaran appeared several times brighter in the sky then than it does now. Plus – 450,000 years ago – Aldebaran shone very close to the very bright star Capella on the sky’s dome. In that distant past, these two brilliant stars served as a double pole star in the astronomical year -447,890 (447,891 BCE).

EarthSky astronomy kits are perfect for beginners. Order today from the EarthSky store

This illustration shows the view from Seen from present-day Arizona in 447,000 B.C., when Aldebaran and Capella served as double pole stars. Illustration via Carina Software and Instruments

At this point, we should probably insert a note about astronomical dating. In ancient times, there was no zero year, so the year AD 1 followed the year 1 BC. However, present-day astronomical calculating is made simpler by equating the astronomical year 0 with the year 1 BC. Thus, the astronomical year -1 corresponds to 2 BC and the astronomical year -2 corresponds to 3 BC. And so on . . .

But back to Aldebaran and Capella as dual pole stars. The identity of the pole star shifts over time, due to the 26,000-year cycle of precession. To read more about that, click into this article about Thuban, another former pole star.

Still, how can it be, you might wonder, that the stars Aldebaran and Capella were once so near each other on the sky’s dome? They’re not especially close together now. Aren’t the stars essentially fixed relative to one another? The answer is that, yes, on the scale of human lifespans, the stars are essentially fixed. But the stars are actually moving through space, in orbit around the center of the galaxy. In our solar system, galaxy and universe … everything is always moving. So the sky looked different hundreds of thousands of years ago than it does today.

Here’s another kind of motion you might pay attention to tonight. It’s the spin of the Earth you’re standing on, which causes the moon and Aldebaran to shift westward throughout the night. And yet another motion … the moon is also going eastward relative to the fixed stars (which we now know aren’t really fixed), because of the moon’s orbit around Earth.

In other words, tonight and for the next several days, if you look carefully over a period of hours (or from one night to the next), you can watch the moon traveling eastward in front of the constellation Taurus.

Aldebaran is a noted star of the Zodiac – the band of stars in front of which the sun, moon and planets make their rounds.

But Aldebaran wasn’t always a star of the Zodiac. Some 450,000 years ago, Aldebaran and Capella teamed up together to serve as Earth’s double north pole star!*

*Source: Page 363 of Mathematical Astronomy Morsels V by Jean Meeus

Bottom line: The moon occults – or covers – the bright star Aldebaran on January 19, 2016. We give occultation times for four major U.S. cities and links to timings elsewhere. Plus we tell the story of Aldebaran as the pole star some 450,000 years ago, when it had the company of a fellow bright pole star, Capella.

from EarthSky http://ift.tt/20b7jTE

The moon was to the west of Aldebaran yesterday, on January 18.

Tonight – January 19, 2016 – the waxing gibbous moon passes in front of – or occults – Aldebaran, an ex-pole star and the brightest star in the constellation Taurus the Bull. So that’s why Aldebaran is missing from the above sky chart – because we’re depicting it with the moon is covering it. For an idea of Aldebaran’s whereabouts, check the chart at right for the day before, on January 18.

From much of North America, the moon will occult – cover over – Aldebaran for an hour or so during the nighttime hours on this date. Aldebaran will disappear behind the moon’s dark side and reappear on its illuminated side. We give the local occultation times for four US cities:

New York, NY Eastern Standard Time (EST)
Occultation begins: 9:31 p.m. EST
Occultation ends: 10:43 p.m. EST

Kansas City, MO Central Standard Time (CST)
Occultation begins: 7:47 p.m. CST
Occultation ends: 9:03 p.m. CST

Denver, CO Mountain Standard Time (MST)
Occultation begins: 6:29 p.m. MST
Occultation ends: 7:46 p.m. MST

Los Angeles, CA Pacific Standard Time (PST)
Occultation begins: 5:03 p.m. PST
Occultation ends: 6:14 p.m. PST

View larger Occultation map via IOTA (International Occultation Timing Organization). All places within the solid white lines can see the occultation of Aldebaran sometime during the nighttime hours on January 19-20, 2016.

Click here to find out the occultation times for your locality in Universal Time (UT). To convert Universal Time (UT) to your local time:

Atlantic Standard Time = UT – 4 hours
Eastern Standard Time = UT – 5 hours
Central Standard Time = UT – 6 hours
Mountain Standard Time = UT – 7 hours
Pacific Standard Time = UT – 8 hours.

Occultation of Aldebaran on January 19-20

Aldebaran, the ex-pole star

Although Aldebaran now reigns as a star of the Zodiac, did you know that Aldebaran is a former pole star?

It’s true, and it’s a fascinating story.

Many people know that Polaris is the present-day North Star, but few know that Aldebaran reigned as the North Star some 450,000 years ago.

What’s more, Aldebaran appeared several times brighter in the sky then than it does now. Plus – 450,000 years ago – Aldebaran shone very close to the very bright star Capella on the sky’s dome. In that distant past, these two brilliant stars served as a double pole star in the astronomical year -447,890 (447,891 BCE).

EarthSky astronomy kits are perfect for beginners. Order today from the EarthSky store

This illustration shows the view from Seen from present-day Arizona in 447,000 B.C., when Aldebaran and Capella served as double pole stars. Illustration via Carina Software and Instruments

At this point, we should probably insert a note about astronomical dating. In ancient times, there was no zero year, so the year AD 1 followed the year 1 BC. However, present-day astronomical calculating is made simpler by equating the astronomical year 0 with the year 1 BC. Thus, the astronomical year -1 corresponds to 2 BC and the astronomical year -2 corresponds to 3 BC. And so on . . .

But back to Aldebaran and Capella as dual pole stars. The identity of the pole star shifts over time, due to the 26,000-year cycle of precession. To read more about that, click into this article about Thuban, another former pole star.

Still, how can it be, you might wonder, that the stars Aldebaran and Capella were once so near each other on the sky’s dome? They’re not especially close together now. Aren’t the stars essentially fixed relative to one another? The answer is that, yes, on the scale of human lifespans, the stars are essentially fixed. But the stars are actually moving through space, in orbit around the center of the galaxy. In our solar system, galaxy and universe … everything is always moving. So the sky looked different hundreds of thousands of years ago than it does today.

Here’s another kind of motion you might pay attention to tonight. It’s the spin of the Earth you’re standing on, which causes the moon and Aldebaran to shift westward throughout the night. And yet another motion … the moon is also going eastward relative to the fixed stars (which we now know aren’t really fixed), because of the moon’s orbit around Earth.

In other words, tonight and for the next several days, if you look carefully over a period of hours (or from one night to the next), you can watch the moon traveling eastward in front of the constellation Taurus.

Aldebaran is a noted star of the Zodiac – the band of stars in front of which the sun, moon and planets make their rounds.

But Aldebaran wasn’t always a star of the Zodiac. Some 450,000 years ago, Aldebaran and Capella teamed up together to serve as Earth’s double north pole star!*

*Source: Page 363 of Mathematical Astronomy Morsels V by Jean Meeus

Bottom line: The moon occults – or covers – the bright star Aldebaran on January 19, 2016. We give occultation times for four major U.S. cities and links to timings elsewhere. Plus we tell the story of Aldebaran as the pole star some 450,000 years ago, when it had the company of a fellow bright pole star, Capella.

from EarthSky http://ift.tt/20b7jTE