Composite image by Christmann. Background
(Quintuplet Cluster), credit NASA Hubble Telescope. Inset (WR 104:
Pinwheel Star), credit U.C. Berkeley Space Sciences Laboratory,
W.M. Keck Observatory.
Enjoy our starry night skies
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.
April 2008 Night Sky
Like a well-regulated clock, WR 104, known as the “Pinwheel,”
beautifully spins about its axis every eight months. The cosmic
wonder, discovered eight years ago in the constellation Sagittarius,
is formed by two massive, hot stars locked in orbit around each
other. Like most super-giants leaning toward old age, these stars
are puffing off material. Their circular orbits are marked by the
Looking in the direction of Sagittarius, astronomers have located
as many as five of these pinwheel-type binaries. Most of them are
close to the center of our galaxy, approximately twenty-five thousand
light-years away (147 million-billion miles). Astronomers have determined
that stars in the pinwheels are massive and short-lived, nearing
the end of their lives. Such massive stars will end their existence
in a supernova. Massive binary star systems like these actually
explode three times in their lives. There are two explosions when
each of the pair separately undergoes a core-collapse supernova.
Then, a third explosion occurs as the remnants of the two stars
spiral into each other and merge.
WR 104 is a bit closer to Earth, estimated to be only eight thousand
light-years away. Unfortunately, one of the pair of stars has been
classified as a Wolf-Rayet type. Astronomers believe that these
types of stars are “ticking time-bombs,” on their final
countdown to exploding.
When a Wolf-Rayet goes supernova, according to Peter Tuthill, an
astronomer at the University of Sydney, they may emit an intense
beam of gamma rays from their rotational poles like a searchlight
beam. If that happens, we really do not want Earth to be in the
way. Unfortunately, data published in the March 1st issue of Astrophysical
Journal indicates we may be in that searchlight, though more observations
are needed to confirm that. Even at eight thousand light years distance,
the long-term effects of the gamma rays would be devastating to
our atmosphere and ozone layer, allowing the Sun’s UV rays
to reach the surface.
But this may not be the end for Earth—there are still many
variables, like how close we actually are to the beam’s center,
and there is still controversy over whether stars like WR 104 are
capable of producing a fully-fledged gamma ray burst in the first
If you have a telescope or good binoculars, take a good look at
Saturn and enjoy its rings. The rings are disappearing. They will
be gone by early September 2009. But don’t worry—they’ll
be back. Over the course of about thirty years, as Saturn orbits
the Sun, the angle of the rings, as seen from Earth, oscillates
up and down. The best viewing of the rings happened in early 2003
when the tilt reached its maximum of twenty-seven degrees, showing
their southern side. Now they are tilting back toward zero degrees
so that we will only see them edge-on. And being less than three
miles thick, they seem to disappear. In another fifteen years, the
rings will be back to full glory. Then we can enjoy a view of the
rings’ northern side.
THE PLANETS AND THE MOON
• Look for Mercury the first week in April rising about thirty
minutes ahead of the Sun in the east. It will be closer to the Sun
as the days pass.
• Venus is also up ahead of the sun, shining brightly in
the east, but it rises earlier each day. Enjoy a great show about
ten minutes before sunrise on the 4th as Venus clears the horizon
with the thin crescent Moon just above and to the right. If you
are careful not to look at the Sun (use the edge of a structure
to block the Sun for safety), use binoculars to find Venus during
the daylight hours using the Moon as a reference.
• Mars is high in the western sky at sunset. • Look
for the Moon and Mars about an hour after sunset on the 11th. Bright
Capella will be to the right of the Moon, Betelgeuse and Rigel below,
and Procyon to the left and a bit below.
• At mid-month, Jupiter is rising at 2:00 a.m. and will be
just slightly less bright than Venus. The Moon joins Jupiter in
the southern sky about forty-five minutes before sunrise in the
southern sky on the 27th.
• Saturn is well up in the southern sky after sunset. Check
out the grouping of the Moon, Saturn, and Regulus an hour after
sunset on the 15th in the southern sky.
• The Moon is new at 9:55 p.m. on the 5th and full at 4:25
a.m. on the 20th. Lunar perigee (224,366 miles from Earth) occurs
on the 7th at 1:30 p.m. Lunar apogee (252,242 miles from Earth)
happens at 3:55 a.m. on the 23rd.
If you have a question or comment for Charlie,
you may email him at: firstname.lastname@example.org.
Astronomical Society hosts star party in Edgewood
On April 11, The Albuquerque Astronomical Society (TAAS) and the
Edgewood Parks Department will host the Edgewood Star Party at Wildlife
West Nature Park, just north of I-40 and just west of the Edgewood
Telescopes will be set up in a flat field, shielded from the highway
light. The field is next to a pole barn, where last year, spiced
apple cider was served. Peer at galaxies in the Virgo and Coma clusters.
See Saturn in the constellation Leo. Gaze at the Whirlpool Galaxy’s
spirals, which grace the night sky. Observe, through telescopes,
resolved stars of the M3 globular cluster.
To get to the park, take I-40 east to the Edgewood exit. Go under
the freeway, and turn left immediately past the highway. Follow
this road approximately a mile to Wildlife West’s entrance.
Observing will commence at sunset. Pets are not allowed in the viewing
area. For information, visit www.taas.org or call 254-TAAS. The
party is free of charge and is open to the general public.
Gear up for Astronomy Day, Cosmic Carnival 2008
This year’s Astronomy Day will once again be celebrated in
New Mexico as a part of Cosmic Carnival 2008. The event is scheduled
for Sunday, April 20 from 12:00 noon to 6:00 p.m. Cosmic Carnival
will partner with the City of Albuquerque’s Fiesta de Albuquerque
in the Old Town Plaza area. The city will close all of the plaza
area to vehicular traffic and create a giant pedestrian zone. This
year’s astronomy and science exhibitors will be located on
Church Street, which is one block north of the plaza behind the
Already a number of exhibitors have signed up to participate. They
include Explora, the New Mexico Museum of Natural History, the Atomic
Museum, the Very Large Array, the Magdalena Ridge Observatory, and
Sunspot. Albuquerque Astronomical Society members are encouraged
to bring telescopes to the event for public viewing. The event is
always exciting and fun and is a good precursor for next year’s
International Year of Astronomy.
For more information, visit www.cosmiccarnival.org.