
The sunspot number on June 20, 2008,
was eleven, with one small sunspot, #999, showing.
Enjoy our starry night sky
Be a considerate neighbor: Reduce nighttime glare.
Shield your outside lights downward, so no glare goes up to dull
the night sky (or into your neighbor’s windows) and enjoy
the beautiful, stars above.
July 2008 Night Sky
—CHARLIE CHRISTMANN
THE SKY IS FALLING!
This is becoming a bit unusual. This has not happened in recent
history! The Sun is dying!! Well, not really, but the sun has gone
quiet—I mean really, really quiet. It has been almost two
years since the Sun produced any significant number of sunspots.
Yes, I know—the bottom of the solar cycle. But that was supposed
to have already happened and the solar activity was expected to
start increasing by now. Some scientists are beginning to wonder.
“It continues to be dead,” said Saku Tsuneta with
the National Astronomical Observatory of Japan. “That’s
a small concern, a very small concern,” because the period
of inactivity seems to be going on longer than normal. Some scientists
think we may be heading into another Maunder minimum.
SUNSPOTS
Sunspots appear as dark spots within the photosphere, the outermost
layer of the Sun. The photosphere is about 250 miles deep, and is
where most of the light is produced. The layer is about ten thousand
degrees Fahrenheit. The temperature within sunspots is a cool 7,800
degrees or so. Being cooler, the sunspots appear as dark blotches
on the face of the Sun. Sunspots are areas of intense magnetic energy.
They act like temporary caps on the boiling matter rising up from
below, and they are the sites of occasional monstrous eruptions
of light and electrified gas. More sunspots generally mean increased
solar activity.
The number of sunspots seen on the surface of the Sun peaks and
falls over an 11.1 year period. During this cycle, the Sun’s
magnetic field flips. The magnetic field is the strongest during
the solar cycle peak and there are lots of sunspots. At the minimum
of the cycle, the solar field is weak and there are few spots.
Sunspots have been observed in the Far East for over two thousand
years, but the Europeans examined them more closely after the invention
of telescopes in the seventeenth century. In 1647, Johannes Hevelius
made drawings of their movements. In 1801, William Herschel attempted
to correlate the annual number of sunspots to the price of grain
in London. The eleven-year cycle was first demonstrated by Heinrich
Schwabe in 1843. There have been several periods in recorded sunspot
history where spots were rare or absent. The first happened between
1645 and 1715 and was called the Maunder minimum. A second, less
severe drought of spots happened from 1795 to 1820 and was called
the Dalton minimum.
WHAT NEXT?
The last solar cycle, which peaked in 2001, was a particularly intense
one, with a surge in solar storms between 2000 and 2002. In fact,
the last three solar cycles were also more active than normal; the
average is around 110 to 120 sunspots on any given day during the
cycle’s maximum. Solar watchers think that such intense activity
in the peak of the solar cycle tends to lead to less activity at
the end of the cycle. Data shows that sunspot activity has been
more intense and lasted longer during the past sixty to seventy
years than at any time in more than eight millennia. However, recent
work by solar scientists studying the periods when our Sun loses
its sunspots, along with data on other Sun-like stars that may be
behaving in the same way, suggests that our Sun may spend between
ten and twenty-five percent of the time in this state.
During the Maunder minimum, for example, Europe and North America
experienced a Little Ice Age. The Little Ice Age was a period of
cooling that occurred after a warmer period known as the Medieval
Warm Period. The Little Ice Age brought bitter winters to many parts
of the world, mostly documented in Europe and North America. During
this period, average global temperatures were one to one-and-a-half
degree Celsius (two to three degrees Fahrenheit) cooler than they
are today. In the mid-seventeenth century, glaciers in the Swiss
Alps advanced, gradually engulfing farms and crushing entire villages.
During the winter of 1780, New York Harbor froze, allowing people
to walk from Manhattan to Staten Island.
What does this mean? Are we entering an ice age? Nobody really
knows. Scientists disagree on the connection between the number
of sunspots and global temperatures. Will there be a new ice age?
Or will temperatures rise? I guess we’ll just have to sit
back and wait… we should know something in fifty to a hundred
years.
THE PLANETS AND THE MOON
• Mercury rises in the east about ninety minutes ahead of
the Sun.
• Venus can be found after sunset in the west. Look in the
northwest sky about ten minutes after sunset on the 3rd to see the
slim crescent Moon join Venus.
• Mars is high in the west after sunset this month. The Moon
will appear to the left of a spectacular line-up in the west with
Saturn, Mars, and Regulus on the 6th. Saturn is above Mars, with
Regulus below.
• Jupiter can be found brightly shining in the southeast after
sunset. On the 16th, look for Jupiter to the upper left of the waxing
Moon an hour after sunset.
• Saturn is high in the west after sunset. Less than one degree
will separate Mars and Saturn one hour after sunset above the western
horizon on the 10th.
• The Moon is new on the 2nd and full on the 18th.
If you have a question or comment for Charlie,
you may email him at: k5cec@yahoo.com.
TAAS hosts talk on the Thinking Telescopes
The speaker for The Albuquerque Astronomical Society (TAAS) General
Meeting on July 12 at 7:00 p.m. will be Dr. Przemek Wozniak from
Los Alamos—"Mining the transient sky with Thinking Telescopes."
This talk will introduce the Thinking Telescopes project, its main
concepts, implementation, and scientific results, with the emphasis
on recent progress in studies of Gamma-Ray Bursts (GRBs), sometimes
referred to as "the largest cosmic explosions since the Big
Bang." The Thinking Telescopes project at Los Alamos National
Laboratory (LANL) is pushing the envelope by developing a network
of fully autonomous optical imaging detectors with the purpose of
continually monitoring the sky in search of rapid transient phenomena
in astronomical objects on time-scales as short as one minute.
The meeting is at Regener Hall on the UNM campus. For information,
call 505-254-TAAS. To obtain a map, visit http://www.taas.org.
Expand your horizons. Join us for an evening of entertainment and
socialization.
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