|
Date: |
Fri, 2 Nov 2007
12:12:04 -0700 (PDT) |
|
From: |
"Glenn A.
Walsh" <gawalsh@planetarium.cc> |
|
Subject: |
RE: Star or
Planet |
|
To: |
"Christina
Grabe" |
|
CC: |
"Glenn A.
Walsh" <gawalsh@planetarium.cc> |
To: Christina Grabe,
From: Glenn A. Walsh,
Project Director,
Friends of the Zeiss
Thank you for the inquiry.
Typically, there are only two objects in the
non-daylight sky
that appear like a star but are much
brighter than any of
the other visible stars. These
are the planets
Venus and Jupiter. And, Venus is often
much, much
brighter than Jupiter.
Currently, Jupiter is only visible in the early
evening sky. In the
early morning sky, Venus is quite
brilliant at
this time. And, as it rises about an hour
or so before
the Sun, this is what you would have seen
in the
southeast just before sunrise.
Venus is shrouded in clouds, and the sunlight
reflected from
these clouds makes it appear as a
bright beacon in
the sky. And, if you use a telescope
or good set of
binoculars, you can see Venus go
through phases
similar to the Moon.
Astronomers rank celestial objects by brightness,
using
"Apparent Visual Magnitude." At the present
time, the
Apparent Visual Magnitude of Venus is -4.2.
In comparison, the Apparent Visual Magnitude of the
Sun: −26.73; Full Moon: −12.6; and the
brightest star
in the night sky, Sirius: −1.47.
Most stars have a positive (+) Apparent Visual
Magnitude.
Venus is so bright that it is often confused for an
airplane or an
unidentified flying object,
particularly when
it is near the horizon [either has
just risen or
about to set]. In fact, when I was
employed with
and Institute
of Popular Science in the 1980s and
early 1990s,
during the evening hours I received many,
many
"UFO" telephone calls from the public, when Venus
was visible in
the sky.
So, whenever you see such a very bright object,
particularly
before sunrise or after sunset [when
Venus is mostly visible], you can be pretty sure that
this is the
planet Venus.
gaw
--- Christina Grabe wrote:
> Subject: Star or Planet
> Date: Fri, 2 Nov 2007 12:10:51 -0500
> From: "Christina Grabe"
> To: <FAQ@planetarium.cc>
>
> In the early morning sky about 6 AM, high in the
> south east sky is a
> very bright object. Is it a star or planet and
> which every one it is,
> would you supply me with it's
name?
>
> Thank you,
>
> Chris
>
>
>
>
> 57th &
>
>
gaw
Glenn A. Walsh
Electronic Mail - < gawalsh@planetarium.cc
>
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