What’s Up in the Sky April, 2007

Constellation Leo

I was in the Holland Peanut Store recently talking to my good friend Paula Fabiano who delighted me with the story of her trip home from vacation. She was on an airplane flying north at sunset when she looked out the right-hand window and saw the rising moon in full eclipse. She was so excited she grabbed her camera to snap some photos. I asked her if she looked out the window on the opposite side to see the sun setting simultaneously, thus witnessing the syzygy about which I wrote last month. But, alas, the movie was just starting and the passengers on that side had pulled the shades. Apparently the pilot missed last month’s column and was not aware of what the passengers were missing.

This month one of the most famous constellations dominates the southern sky. Go out around 10:00 p.m. About two thirds of the way up from the southern horizon you should see bright Saturn and to the east (left) of Saturn is the constellation Leo, the Lion. Leo faces the viewer’s right (west). Look for a backwards question mark or sickle pattern of stars – that’s his head and mane – facing Saturn. To the left is a triangle of stars representing his hind quarters.

At the bottom of the sickle is the star Regulus, The Little King. Although many ancient civilizations had names for this star that were similar in meaning – Malikiyy, the Kingly One in Arabia, and Regia, The Star of the King in ancient Greece, for example – the modern name, Regulus, was given by Copernicus.

Leo’s image appears on coins from ancient Greece and Babylon and observations of Regulus are recorded on Babylonian tablets that date from about 2100 BC.

It is in this constellation that the point from which the famous Leonid meteors appear to radiate is located. The displays were particularly spectacular in 1833, 1866, and 1966, just after the comet that leaves the meteor-causing debris had passed by. Witnesses reported up to 150,000 meteors per hour and said they had a sensation of the earth’s motion through space.

The star Wolf 359 is located in Leo. This extremely faint red dwarf is the third nearest star and one of the least luminous stars known. Another interesting star is Algeiba, the brightest star in the curve of the sickle. It is one of the finest double stars in the sky and a good test for a small telescope.

Leo is home to a fine pair of spiral galaxies, M65 and M66, which can be seen together through a low-power telescope. M95 and M96 are another interesting pair. For more information on how to view these and other objects in Leo, consult a field guide or periodical such as Sky and Telescope or Astronomy magazines, or on the web at http://www.seds.org/Maps/Stars_en/Fig/leo.html.

This month in history:

Apr. 2: First photograph of the Sun – 1845
Apr. 7: Deployment of Compton Gamma Ray Observatory – 1991
Apr. 9: Original seven Mercury astronauts selected by NASA – 1959
Apr. 12: Yuri Gagarin becomes first human in space – 1961
Apr. 12: Columbia is first space shuttle to be launched – 1981
Apr. 16: First captured V2 rocket launched from White Sands, NM – 1946
Apr. 20: Apollo 16 lands on the Moon – 1972
Apr. 25: Deployment of Hubble Space Telescope – 1990
Apr. 28: Eugene Shoemaker born – 1928

Here are this month’s viewing highlights:

Venus shines brightly in western sky at dusk, setting more than 3 hours after sunset. Jupiter rises after midnight and dominates he southern predawn sky. Saturn just west of Leo; rings well placed for viewing with telescope.

Apr. 2: Full Moon.
Apr. 10: Last-quarter Moon.
Apr. 17: New Moon.
Apr. 19: See crescent Moon between Venus and Plieades.
Apr. 24: First quarter Moon near Saturn.

Peter Burkey – SAAA President

What’s Up in the Sky March, 2007

Vernal Equinox and Total Lunar Eclipse

March is usually notable as being the month during which the Sun crosses the vernal equinox marking the first day of spring for those of us in the northern hemisphere.
This year March should also be notable to fans of word puzzles because we will be able to witness syzygy – the alignment of three celestial bodies. The three are the Sun, Earth, and Moon and it happens at sunset this Saturday, March 3. For observers in West Michigan the rising Moon will be engulfed in the Earth’s shadow at that time, an event known as a total lunar eclipse.

Although lunar eclipses occur on average every 1.2 years, this will be the first one since October 28, 2004. And although we will miss the beginning phases of the eclipse which occur before the Moon rises, there are still some unique aspects we may be able to see.

One interesting observation you may want to attempt is to observe the rising eclipsed Moon and the setting Sun at the same time. This may seem impossible due to the perfect syzygy alignment but because light from each object is bent by our atmosphere we are actually able to see the Sun for several minutes after it has set and the Moon several minutes before it rises. Of course, you will need cloudless skies and a clear view of each horizon. Start your search for the rising Moon on the eastern horizon right at 6:30 p.m. Binoculars will help, depending on how clear it is. Being up high will help also – like on Mt. Baldy in Saugatuck. Good luck.

A somewhat easier, but no less unique, observation may also be possible for those viewing with a small telescope or a good pair of binoculars. Beginning at 7:10 p.m., train your scope on the upper right-hand portion of the Moon and watch carefully. By 7:15 you should see a dim star appear from behind the Moon. Normally a star like this would be completely washed out by the bright, full Moon but since the Moon is in the Earth’s shadow, we may be able to witness its appearance – a rare event indeed.

I am very interested to know if any readers successfully observe either of these events. Please email me at pburkey@comcast.net if you do.

This month in history:

Mar. 1: Venera 13 relays first color photos from surface of Venus – 1982
Mar. 8: Voyager 1 discovers first active extraterrestrial volcanoes (on Jupiter’s moon Io) – 1979
Mar. 10: Rings of Uranus discovered – 1977
Mar. 14: Albert Einstein born – 1879
Mar. 16: First liquid fuel rocket successfully launched by Robert Goddard – 1926
Mar. 18: World’s first spacewalk made by Alexei Leonov – 1965
Mar. 23: First photograph of Moon – 1840
Mar. 25 Saturn’s largest moon, Titan, discovered by Christiaan Huygens – 1655

Here are this month’s viewing highlights:

Planets this month: Brilliant Venus continues to climb higher in western sky at sunset during March. Jupiter shines brightly in the south before sunrise. Saturn in ESE at dusk; look for it next to gibbous Moon on the 1st.
Mar. 3: Full Moon; Moon rises during total phase of lunar eclipse.
Mar. 11: Last-quarter Moon.
Mar. 18: New Moon.
Mar. 20: Spring begins at 8:07 p.m. EDT when the Sun reaches vernal equinox.
Mar. 20-21 See crescent Moon near Venus 1 hour after sunset.
Mar. 25: First quarter Moon.

Peter Burkey – SAAA President

Whats Up in the Sky February, 2007

Sirus, The Dog Star

I normally do not joke around when people ask me about the stars, especially when they ask about the star Sirius.

Sirius, also known as the Scorching One or the Dog Star, is prominent in the southern sky at this time of year. Just look to the lower left of Orion and you can’t miss it shining brighter than any other star. It is so bright that some have even observed it in the daytime through a small telescope.

At 8.6 light years, Sirius is the 5th nearest star known. Among naked-eye stars, only Alpha Centauri is closer. It has more than double the suns mass and diameter and, if it were as near as the sun, it would shine over 26 times brighter.

Being the most brilliant of the fixed stars throughout history, Sirius has been an object of wonder to all ancient peoples. Similarities in the Greek, Roman, Arabic, and Egyptian names suggest a common origin from an earlier language, possibly Sanskrit.

The ancient Egyptian calendar was based on Sirius annual first appearance in the predawn sky, announcing the coming rise of the Nile.

References to the star can be found in the writings of Homer, Plutarch, and Virgil as well as in Hindu, Persian, Babylonian, and Chinese records. It is no wonder then that many myths and legends surround the star, some of which are not so old.

In the early 1800’s, observations of Sirius indicated it had an unseen companion orbiting every 50 years or so. Lost in the glare of its parent star, the companion, Sirius B, eluded observation until 1862 when it was discovered near its predicted location by Alvan G. Clark. The 18.5 inch refracting telescope he used is still in service at the Dearborn Observatory of Northwestern University.

Despite some ancient astronaut legends surrounding the African Dogon tribe’s unusual knowledge of this invisible companion, it is an intriguing object to modern astronomers. Sirius B is a white dwarf (the first to be discovered), a star with a mass about equal to that of the sun but a diameter some 40 or 50 times smaller. Thus it is incredibly dense, a cubic inch of its matter weighing over 2 tons! It also attracts material from Sirius which builds up and causes the white dwarf to heat up and eventually collapse. This triggers a new chain of nuclear reactions ending with the star exploding in what is known as a Type I supernova. Such an event, occurring so close and releasing massive amounts of radiation could have dire consequences for us. However, this probably wont happen for a million years.

So enjoy this beautiful beacon of light up in the sky, before it gets serious.

This month in history:

Feb. 1: Shuttle Columbia breaks apart during reentry killing all 7 astronauts – 2003
Feb. 4: Pluto discoverer Clyde Tombaugh born – 1906
Feb. 5: Alan Shepard hits golf balls on Moon – 1971 *
Feb. 15: Galileo Galilei born – 1564
Feb. 18: Pluto discovered – 1930
Feb. 19: Nicholas Copernicus born – 1473
Feb. 20: John Glenn is first American to orbit Earth – 1962
Feb. 24: Detection of first pulsar (by Jocelyn Bell in 1967) is announced – 1968

Here are this month’s viewing highlights:

Planets this month: Venus, in SW at dusk, climbs higher in the sky as month progresses. Mercury may be visible near Venus as month begins. Jupiter is visible before sunrise in SE. Saturn rises in the east at dusk and is visible all night.
Feb. 2: Full Moon
Feb. 10: Last-quarter Moon.
Feb. 11-12: View crescent Moon, Antares, and Jupiter close together in SSE one hour before dawn.
Feb. 17: New Moon.
Feb. 19: Venus close to crescent Moon in WSW 40 minutes after sunset.
Feb. 24: First quarter Moon.

Peter Burkey – SAAA President