UCL Observatory (UCLO)


UCLO News Archive 2006

Indirect Observation of Exo-Planets from UCLO

The Celestron C14 and SBIG STL6303E CCD camera have been commissioned over the summer, and are ready for use in student teaching in the 2006 autumn term.

Outside teaching hours a UCL 4th-year project student, Dan Smith, and project supervisor, Dr. Steve Fossey , are using the telescope and CCD to observe the transits of extrasolar planets.

Observations of the star HD189733 were taken in July and August 2006 during two transit events; a sequence of several hundred images were obtained on each night.

hd189733 Star field

Photometry of the star's brightness variations, measured relative to other stars in the field, reveals how the star's light fades very slightly (a few percent) while its planetary companion passes in front of it as viewed from Earth.

hd189733 transit

The planet orbits its host star in just over 2 days, and the total transit lasts just under 2 hours. Modelling of the light curve can provide estimates of the planetary radius: the latest results on this system indicate the exoplanet is about 15 percent bigger than Jupiter, while the star is about 20 percent smaller than the Sun. Such observations are very important for determining the nature of such planets - so-called "hot Jupiters" - and addressing detailed questions concerning their origin in exo-planetary systems.

NAGTY Day 2006 at UCLO

On 15 August 2006, the facilities at UCLO were used by the NAGTY (National Academy for Gifted and Talented Youth) Astrophysics Summer School 2006 . This is a two-week residential course for 11-16 year-olds, led by Dr Adam Burnley.

The theme of this year's summer school was the Sun, from solar activity and the solar cycle through to solar evolution.

NAGTY day 08

For most of the sixteen participants, this was their first visit to an astronomical observatory. After a tour of the telescopes, the students embarked upon a day of activities. UCLO made available three telescopes for solar observing. These were fitted with white light and H-alpha filters, and (when the weather eventually cleared up!) everyone had the chance to observe at first hand sunspots and prominences. The data obtained were incorporated into the students' project research work, the results of which were presented at the end-of-course conference at Imperial College.

NAGTY day 08

In addition, the students undertook a computer-based experiment to determine the rotation period of the Sun using sunspot data. There was also the opportunity to study a number of Mount Palomar Sky Survey prints, searching for objects such as interstellar dust clouds and planetary nebulae.

The image above was generated by Mick Pearson using a Tele-view SolarMax 50 H-alpha telescope, an Astrovid black and white video camera and a DVD-Recorder.

The video from the DVD-Recorder was loaded onto a computer via a capture card and aligned and stacked using RegiStax. Colour and sharpening was done in Adobe Photoshop.

Solar prominence on 11 May 2006

On 11 May 2006 Mike Pearson, Technician at the Observatory, set out to record a transit of the Intenational Space Station across the center of the sun. Unfortunately this couldn't be observed, possibly due to a manouvre of the space station earlier in the day.

However, at the same time a massive solar prominence was visible, one of the biggest observed here at UCLO.

Image of a huge solar prominence taken by Mike Pearson at UCLO on May 11 2006

The image was taken through a SolarScope Solarview 50 telescope piggybacked on a Meade 7" Maksutov. The camera is a Minitron 12vl (HAD) CCTV video camera.

The footage was recorded on a DVD recorder and then copied to a PC for processing in Registax, combining about 500 frames.

Contrast and brightness adjustment and addition of colour was done in Photoshop.

Finally three false colour images were combined in Astroart.

Progress on the C14 Telescope

New equipment has been installed on the C14:

Progress on C14 Telescope
  • An in-house fabricated dew-cap which allows use of the original dust cap. A new counter balance plate, weights and fixing screws are being made for the front end to balance out the new equipment. Also a third counter weight has been fitted to the R.A. axis.
  • A Van Slyke Engineering Omega 2.7" focuser. It is controlled by a Robo-Focus stepper motor through CCDsoft software and also controls the camera.
  • A VSE "Mega-Port Sidewinder", which allows the use of either of the two installed eyepieces (or additional cameras) by rotating an internal mirror or sliding out the mirror for using the main CCD camera. It also has a fourth port to allow for an auto-guiding camera.
  • A new SBIG STL 6303-E CCD camera, complete with additional remote guiding head, is mounted on the back end of the VSE "Mega-Port Sidewinder". The chip has 6.3 million 9x9µm pixels in an array of 3072 x 2048 giving a field of view of 18 x 24 Arc minutes on the C14. The camera's USB 2.0 connection allows a full frame download time of approximately 15 seconds. To overcome cable length restrictions we installed a powered USB extender utilising Cat5 cable, extending the USB range from 5 to a maximum 50 meters.
  • A second computer screen keyboard and mouse have been installed on a custom built mounting in the dome for demonstration and maintenance purposes. A third screen/TV monitor in the control room enables us to control the CCD camera and view images from it and video cameras fitted to the telescope.
  • A stainless steel railing has been fitted around the pillar to prevent personal injury or mechanical damage when slewing the telescope.

In addition, a purpose-built table will be constructed to fit on the circular raised floor area to optimise the observing platform workspace.

SBIG STL 6303-E CCD camera, "Mega-Port Sidewinder" and     VSE Omega 2.7in focuser.


The Partial Solar Eclipse on 29 March 2006 seen from UCLO

WARNING: Under no circumstances look at the sun through an unfiltered telescope.

The day started out with a thick cloud cover.

Thankfully the weather cleared up a bit just in time, providing enough opening in the cloud cover to observe the event. The second image below was taken without any filter - the filtering was done by the clouds. 

Eclipsed sun

morning sky from uclo

We were filming the sun in H-alpha throughout the event, using first a colour PlanetCam and later a black-and-white Astrovid 2000 on our Solarscope. This was piggy-backed on our 10in Meade telescope. From this footage we extracted the stills below.

Stages of the eclipse

We also had departmental staff and postgraduate students based at Gower Street visiting the Observatory. With the weather playing along they did not regret having made the short trip to Mill Hill.

Staff and postgraduate students observing visually with the Fry and H-alpha solar filter.