Flamsteed Astronomy Society

An eclipse evening with Dr Francisco Diego

— October 6, 2006

Francisco talked to us about his experiences at the 2006 total eclipse on March 29th.  Francisco says he saw his first eclipse in 1970 — he must have been the only 5-year old in Mexico with a degree in astrophysics!   Since then he must have seen dozens of eclipses :  his laptop is loaded with photographs of all kinds from them;  and still he strives to get the perfect set of shots, and frets if his carefully-laid plans don’t go perfectly.  Turn on an eclipse programme on the TV, or open a book on the subject and, very likely, there will be Francisco.

For the March 2006 total eclipse, Francisco travelled to Turkey near Manavgat, with a group from the UCL Diploma course.  He gave us a run-down on his standard ‘eclipse kit’.  He takes about 6 instruments and an iPod loaded with audio of his planned actions during totality — usually he has around 20 seconds spare to actually look at the eclipse!  Otherwise he’s very busy for the 4 minutes or so, running the cameras, and setting filters.

Among his many talents, Francisco is renowned for his ability to extemporise workable equipment with every-day items.  His eclipse kit makes extensive use of plastic from empty juice cartons (the filters slide out very easily) and bits of 4x2.   We’ve always said he could make a cyclotron from some cereal packets and a bottle of washing-up liquid.

He has an 80-mm refractor mounted with a celostat (moving mirror which reflects the image up the fixed telescope tube), a motorised equatorial mount carrying 3 instruments, and 2 tripods with wide-angle and fish-eye instruments.

We were treated to a full review of Francisco’s shots from the eclipse plus a selection of striking pictures taken by other people.   Among the most breathtaking are composite images of the corona built-up with image-processing software from a range of exposures taken during totality.   Equally, shots of the Moon’s shadow racing across the Earth, taken from space, are brilliant.  Click on the thumbnails here for links to the original websites.

Francisco reviewed the ‘flash spectrum’ taken during totality through a diffraction grating, and explained something of the history of discovery using these — the discovery of Helium in the Sun before it was found on Earth, and the mistaken identification of the new element ‘Coronium’ which turned-out to be multiply-ionised Iron.

Francisco is already busily planning his expeditions to Siberia for 2008 and China 2009 when totality will last nearly 6 minutes!  He’ll have an extra 2 minutes actually to watch what’s happening.   Time for a coffee perhaps?


Francisco Diego.

1991 La Paz, Baja California,  by Francisco (Williams College)

BBC Mundo.com — June 2001

‘Corona 1’ from Francisco’s photo gallery on the Cosmic Skies site


Click on the pictures to link to the original sites

1991 La Paz, Baja California,  radial filter image by Francisco (Williams College)

2006 Mar by Jean Mouette, equipe de Serge Koutchmy IAP-CNRS-UPMC

Moon’s shadow 1999 August from MIR space station

Coronal composite image by Fred Espenak

Flash spectrum by Fred Bruenjes