The beginning of a new year is usually a good time to both
reflect on the past year and its achievements, and to look ahead and set some
reasonable goals for the upcoming year.
In 2016, I made it my goal to get out and observe on every clear night I
could. For my galaxy observing I
require nearly pristine, dry skies. So
to compensate for Essex County skies, I needed many different types of objects
that could be observed at Hallam if under less than perfect conditions. It was a good year for planets; I also did
some remarkable double star work, and I even got back into lunar
observing. I managed to observe on 72
different nights in 2016. By
comparison, 2017 saw me under the stars only 34 times. Had my goals changed? Not by much. I missed the April dark sky session because of travel plans, and
ended up missing three good nights as a result. Even so, the weather last year was often less than ideal for
astronomers. Was it just one of those
years? I hope so. If I could make one wish upon a falling
star, it would be for more frequent clear nights (not counting those
beautifully clear nights around a full moon!).
While January is a great time to look back on the year’s
notes, and to plan new observing goals, it is often a terrible time to be
outside setting up a big scope. The
nights in deep winter are often more suitable for naked eye and binocular
observing than for any telescopic work.
It is also a great time for some armchair astronomy. I like pulling out my old Olcott book and
glancing through it near a warm indoor wood fire.
William T. Olcott, in his
Field Book of the Skies, divided the night sky into seasonal work. His winter constellations include Taurus,
Orion, Lepus, Canis Major, Monoceros, and Eridanus. Using a telescope I have completed observations of NGC and other deep sky objects in Taurus,
Lepus, and Monoceros. My clipboard is
now prepared for Orion, and includes a grueling list of 178 winter
objects. However, before trying to navigate
outside with freezing toes and fingers using my 12” Dob, it is always a good
idea to explore some of the constellation with naked eye and 8 x 35 binoculars
first.
It is not surprising how many
sky-watching novices think that stars are only white. When colourful stars are presented, it can be an astonishing
revelation for them. Comparing Rigel
and Betelgeuse with the unaided eye, a difference in colour is apparent. However, using binoculars the difference is
much more astounding. If you are showing
the orange and red star to a beginner, you might also make mention of Professor
Michelson (1852-1931). A number of
interesting facts can be mentioned regarding this American physicist (born in
modern-day Poland). He was the first
American to win a Nobel Prize in the sciences, for one thing. His main work was in refining measurements
of the speed of light. However, it was
his work in interferometry that brings his name into Olcott’s book, in
conjunction with the star Betelgeuse.
This star became the first one, other than our Sun, to have its diameter
measured (in 1920-21). Michelson’s interferometer design is still in use today
at major observatories. Incidentally, Betelgeuse is 1.64 billion km in
diameter. Our sun, by comparison, is 1.39 million km. But wait, there’s more! In popular culture, no less a man than Ben
Cartwright helped Michelson get his career started. In the “Look To The Stars” episode of Bonanza, broadcast in 1962,
the 16 year old budding scientist (played by actor Douglas Lambert) is aided in
his struggle for admission to the US Naval Academy by the Cartwrights. Michelson did live in Nevada at that time in
his life! The episode can be watched on
Youtube.
Now it’s time for a look at
the Great Nebula. Though it presents a
distinctive mystery to the naked eye, in binoculars the mystery at least
becomes a more beautiful one. I have
trouble with the trapezium star in hand-held binoculars, but with a steady hand
the area makes for fun sweeping. Olcott
suggests that it was a Swiss Jesuit by the name of Cysatus, in 1618, who made
the first report on the nebula. His
full name was Johann Baptist Cysat (c. 1587-1657), and his main interest as an
astronomer was in observing comets. He
was one of the first to make astronomical and scientific use of a
telescope. Even in 1804 his
descriptions of comets were still among the best available. Here is Cysat’s brief description of the
Great Nebula:
“Another of these phenonmenon
in the heavens is the congeries of stars at the last star of the Sword of
Orion, for there one can find a similar congestion of some stars in a very
narrow space, and all around and in between the stars themselves is a diffused
light like a radiant white cloud.”
We actually suspect now that the first notated observation
was in 1610, by Nicholas Peiresc, though he was silent on the nebula
afterwards. Surprisingly Galileo did
not mention it in his early observations of 1609 and 1610, though he did map
the stars of Orion. Over the years
hundreds of descriptions have come down to us.
I will leave this topic with Olcott’s own description:
“…The
nebula is a stupendous mass of gas in a state of violent agitation, a gigantic
whirlpool. Even when viewed with an
opera or field glass the star Theta Orionis appears to be enveloped in a haze
which indicates the presence of the great nebula which is a glorious and
wonderful sight in a large telescope.
Words fail to describe its beauty.”
Oddly enough Olcott goes on to describe the Horsehead
Nebula in the unaided eye and field glass section of his Orion section. The Belt stars, where we will finish up our
cold winter’s night viewing, point in one direction towards Aldebaran in
Taurus, and in the other down towards Sirius in Canis Major. There is fine sweeping in those areas, too. From bottom to top the belt stars are
Alnitak, Alnilam, and Mintaka, all around 2nd magnitude. These stars have attracted attention since
the dawn of human sky gazing. The Orion
correlation theory holds that there is a correlation between the three largest
Egyptian pyramids and the three belt stars in Orion. That itself is worthy of some future Aurora article, and
certainly worth a casual mention at a winter star party.
Wishing everyone clear skies in 2018!
Mapman Mike
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