Transcript Astronomy Club 2013

Astronomy Club 2013
Navigating The Night Sky
Website Review:
Telescopes for your use locally:
Teleview 72mm GoTo
Scope w/ Manual
Alignment
Newtonian 8”
All Manual Control
(Kept at ANA)
Meade 10” GoTo w/
Auto-Alignment
(Being delivered)
Lunt 60mm Solar Scope
on LX75 Mount w/ motor
drive
Images tend to reverse and flip based on the type of scope you are using and whether
you are using a diagonal.
The larger a scope is DOES NOT mean that objects will appear bigger. It ONLY means there is
greater light gathering capability and thus images look brighter, more detailed, and you will be
able to see fainter objects.
E.g. The Andromeda galaxy seen by a
small telescope………
……vs the Andromeda galaxy seen by a
telescope with a larger aperture.
Star’s brightness are measured in the Magnitude Scale:
The scale is counter-intuitive:
• Faint objects are on the positive end of the scale
• Bright objects are on the negative end of the scale
58 Magnitudes separate the brightest object from the faintest.
This is equivalent to a brightness ration of 200 billion trillion
times.
How the sky moves:
• Rotates around the North Celestial Pole (NCP)
• Polaris is the North Star, but is 1 degree from
the NCP
• NCP rotates around the sky every 26,000yrs
• 1 revolution in 24hrs (ish)
• Stars appear to rise 4 mins earlier each night
• Celestial Coordinates similar to Lat/Long
• Lines of Latitude and Longitude balloon out
from the earth and onto the night sky:
• Latitude = Declination (+ above the
equator. – below the equator)
• Longitude = Radial Ascension (360
degrees divided by a 24 hour scale)
• Your latitude equals your declination in the sky.
Examples:
• Earth’s equator 0 latitude is 0 declination
• 33 Latitude at San Diego is +33 declination
Understanding The Sky Around Us: Celestial Coordinates
• Zenith: Point in the sky directly above your
head
• Meridian: Imaginary circle perpendicular to
local horizon up through the Zenith and back
through the south pole
• Ecliptic: Path that the sun and planets trace
along the celestial sphere
How do we measure things in the sky?
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Through a telescope, you see a field of view
(FOV) of 1 degree or less
Less than 1 degree are arcminutes, or “minutes
of arc”.
60 arcminutes in one degree
1 arcminute is 1/60 degree
The symbol for arcminutes is ‘
The full Moon is about 30′ (thirty arcminutes)
across. Coincidentally, so is the Sun. Therefore
we have an eclipse.
An arcminute is divided into 60 arcseconds, or
“seconds of arc”
1 arcsecond is 1/60 arcminute or 1/3600 degree
The symbol for arcseconds is “
The face of Jupiter is about 50″ across
A good optical telescope in steady skies can
resolve down to about 1″ (one arcsecond).
Here’s a Handy Tool to use…
The Autumn Sky
The Winter Sky
The Spring Sky
The Summer Sky
The Moon…In a Nutshell
• Maria: dark lava seas on the Moon’s
surface. The newest parts of the
Moon. How do we know?
• Craters: Created by asteroid/meteor
impacts. Some show high ridges and others
show debris fields.
• Mountain ranges: Mons that tower
thousands of feet above the lunar surface
• Cracks and fault lines: Much like earth.
Geology is not just a field of study for
Earth.
The Phases of Venus:
On the website: Excellent Starting guide
Let’s Go Oberving!!!!!!!!