Download - Beginners Astronomy
BEGINNERS ASTRONOMY
Martin Crow Crayford Manor House Astronomical Society
Planetary observing and Imaging
Last time
Martin Crow Crayford Manor House Astronomical Society
Lunar observing using a telescope:
Using charts / maps of the Moon
Things to look out for
Grazing occultations
Drawing / sketching
Safe Solar observing using binoculars and a telescope:
Do’s and don’ts
Ways to observe safely
What to see in white light
Other ways to view the Sun
This week:
Martin Crow Crayford Manor House Astronomical Society
Observing the planets
Naked eye
Telescopically: Eye
Camera
Webcam
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
The ‘classical’ planets have been known since ancient times.
They were noted as different from other stars because they were not ‘fixed’and the Greeks called them ‘Asteres Planetai’ or wandering stars.
The ‘classical planets are: Mercury, Venus, Mars, Jupiter and Saturn although the Greeks would have included the Moon and Sun with these.
All of the classic planets can be viewed with the naked eye.
Naked eye
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
Why do we only see Mercury and Venus in the morning and evening twilight sky?
Venus can be seen in the day light sky when well placed.
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
Why when we observe the planets naked eye can we not see them as disks?
The unaided eye can generally only resolve about 3 arc minutes at best.
Celestial body Angular diameter
Sun 31.6′ – 32.7′
Moon 29.3′ – 34.1′
Venus 9.565″ – 66.012″
Jupiter 29.800″ – 50.115″
Saturn 14.991″ – 20.790″
Mars 3.492″ – 25.113″
Mercury 4.535″ – 13.019″
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
What you will see will be very much determined by:
With a telescope
The seeing.
Magnification
The physical properties of the telescope
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
Seeing
The better the seeing the more detail you will see.
Good seeing is generally associated with misty foggy weather when the air is very still.
The higher the object is in the sky the better the seeing.
Seeing is often disturbed around trees and over buildings.
Observing planets is not so affected by light pollution.
With a telescope
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
With a telescope
Observing using a long focal length telescope will normally give best results.
Magnification – how to work it out.F f
Magnification = F divided by f
Example: F = 500 f = 10 500/10 = 50
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
Resolution.
The finest detail that a telescope can see is its angular resolution.It is equal to 1.22λ/D (radians).Where λ = wave length in meters.D = the diameter of the object glass / primary mirror in meters.What this says is that to see more detail you need a bigger diameter.
With a telescope
The physical properties of the telescope
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
With a telescope
Features on Jupiter's surface
Shadow transits and the motion of the Galilean moons
Phases of the inner planets Venus and Mercury and any visible surface detail.
Things to observe and do:
Keep notes / drawings in your observing log book
Observe Saturn's beautiful ring system and moons
Make use of tables and charts to aid and plan your observing
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
With a telescope
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
With a telescope and camera
The cameras automatic metering needs to be over ridden.
The ISO needs to be set to 100 or 200 – experiment. Note that thehigher the number the grainier the image will be i.e. less detail.
Exposures between 1/5 sec and 1/60 are normal.
If your camera has a histogram use it to help you get the best exposure.
How to:
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
With a telescope and camera
Jupiter
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
With a telescope and camera
Saturn
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
With a telescope and camera
Image of Jupiter taken using film (1990).
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
With a telescope and webcam (Lucky dip imaging)
What you need:
A webcam with CCD sensor
Adapter and infrared blocking filter
A laptop and free software from the internet – Registax or Avistack.
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
With a telescope and webcam (Lucky dip imaging)
How does it work?
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
With a telescope and webcam (Lucky dip imaging)
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
With a telescope and webcam (Lucky dip imaging)
Registax in action – hopefully!
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
With a telescope and webcam (Lucky dip imaging)
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
With a telescope and webcam (Lucky dip imaging)
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
Images by Simon Dawes
With a telescope and webcam (Lucky dip imaging)
Observing the Planets
Martin Crow Crayford Manor House Astronomical Society
Any questions?
Martin Crow Crayford Manor House Astronomical Society