Optical Astronomy Final Year Double Honours Presentation Eoin Cartwright & John Loughran. Supervisor: Dr Créidhe Ní Shúilleabháin

Overview Theory Telescope Setup Initial Observing CCD Setup Telescope Interfacing Development Filter Wheel Design

Refracting Telescope Lens Chromatic aberration

Reflecting Telescope Newtonian Reflector

Reflecting Telescope Cassegrain Reflector

Reflecting Telescope Schmidt Cassegrain Reflector

Telescope Used

Meade Lx200 Schmidt Cassegrain Mirror diameter = 10” or mm Focal length = 2500 mm Focal ratio = f/10 Manual/handset control

Telescope Mount Type Azimuthal mount Stable More difficult to track objects

Telescope Mount Type Equatorial mount Harder to construct Easier to track objects

Telescope Setup Meade Superwedge Previous years Azimuthal mount Track 5 mins approx. This year Equatorial mount Track 30 mins approx. Rough Polar alignment Precise Polar alignment

Rough Polar Alignment Finding North Levelling the mount Obtained Latitude using GPS = 53°22´58.4"

Rough Polar Alignment Dec = 90° HA = 0 °

Precise Polar Alignment Assumes Rough Polar Alignment procedure completed Alignment procedure initiated using handset Telescope attempts to align with Polaris Centred on Polaris using N,S,E,W direction keys Scope Slews to another star (Aldebaren, Hamal)

Precise Polar Alignment Located this star using chart Centred scope on this star using N,S,E,W direction keys Process complete Can now use handset to find a star

Initial Observations Saturn, rings, Titan Jupiter –Callisto, Europa, (Jupiter), Io, Ganymede M42 nebula Andromeda galaxy, nucleus Iridium satellite

Saturn

M42

Observatory and Dome Shelf Seal floor and secure tripod Network computers

Software Setup CCD (Charge Coupled Device) Camera setup Epoch 2000, PictorView –software for CCD Configure Pictor for CCD, 9600 baud

CCD Setup Flip mirror –align Focus CCD –rough –fine

Telescope Interfacing Development Telescope handset Allows access to telescope functions Get R.A, Dec Find

Reasons for development Provides more convenient control –Particularly when using CCD camera Back up –Repairs etc Versatile –New handset needed for increased functionality

Replica Telescope Handset Buttons separated Buttons added Connect Quit LED

First Steps Sample Lab Windows, Lab View programs Short RS232 cable Sent text messages between two personal computers Chose to use Lab Windows Modified Lab Windows to send telescope Commands

Reduced Lx200 Command Set

Reduced Handset Replica

Connection Panel

Cable Configuration

Further Development Complete Handset functionality Give telescope co-ordinates Star map Integrate with CCD imaging software

Filter Wheel Colour imaging - RGB R ed G reen B lue Photometry - UBVRI U ltraviolet B lue V isual R ed I nfrared

L V = luminosity using Visual (green) filter L Vo = luminosity of reference star m V = apparent magnitude of star using V Effective Temperature

Acknowledgements Dr. Créidhe Ní Shúilleabháin David Watson Bill Lanigan Bart Busschotts Dr. Nicola Murphy Others…..