Longhouse Bursary project

Dawn Pilot

With Scott Farlow and the other bursary artists, David Boultbee, Laurence Payot, Theo Price, Elaine Speight at West Bromwich city centre and on the top floor of the West Bromwich Premier Inn, in December 2010.

I timed the event by the phases of dawn twilight, of which there are three:
Astronomical twilight, Nautical twilight, Civil twilight.

The times for these are shown on timeanddate.com


So we met at at 5:45am towards the beginning of Astronomical twilight and went for a walk around the central area of West Brom! It appeared completely dark, but this period is when it is first possible to measure a lightening of the sky, even it isn't really perceptible. This phase starts with the sun 18 degrees below the horizon.

The aim of the walk was to observe the town outside of our regular waking/working hours.

Longhouse Bursary project

Dawn Pilot

After a frosty walk around West Brom crossing paths with a few early workers, but mostly seeing the streets deserted, we returned to the Premier Inn and repaired to a warm room at the top corner of the building.

The high windows formed an L-shape giving a views over an 180 panorama, and looking down onto a main road into the town centre... and with Birmingham central on the eastern horizon. We tilted open the windows to be able to follow the changes outside better - to hear the outside, and feel the temperature of the air.

But as we settled in to watch from 6:20am through to an 8am sunrise we were glad not to be outside for the next two hours at temperatures not much above 0'C.

Longhouse Bursary project

Dawn Pilot

Nautical Twilight is the next phase of dawn - starting with the sun 12 degrees below the horizon and spanning light conditions from being able to start to make out outlines of objects outside and getting lighter but not getting to the point of easily being able to work (or play sports!) outside. Sometimes referred to as 'the blue hour' by painters and photographers. Street lights are still on for this period.

On 9 December this phase was from 6:31am to 7:14am

We watched, drank tea, photographed, noted changes... the many shifts in the colour and lighting of the sky, shop lights coming on, traffic picking up. A dark cloud seemed to rest right across the horizon, but the breaks in this deep blue block framed the lightening sky dramatically. Photos below at the time of transition from Nautical Twilight to Civil Twilight.

Longhouse Bursary project

Dawn Pilot

Images: Shifting light and increasing illumination of the sky, photographs taken during the pilot dawn watching gathering, December 2010.

Click on an individual image for a close up.

Longhouse Bursary project

Dawn Pilot

Civil Twilight and Sunrise: On December 9th 2010, civil twilight started at 7:14am and ended at 7:54am with sunrise.

Civil twilight is the final phase of the dawn, with the sun now 6 degrees below the horizon. In this time the horizon becomes clearly visible, and ground objects progress to becoming visible too, and during this period there starts to be sufficient light to undertake activities outside, and street lights may be timed to switch off during this time.

We were surprised to see how much change took place after sunrise. The red glow on the horizon was just after sunrise - the time when the upper edge of sun becomes visible over the horizon - but this soon faded to a sky of greys, and then, around half an hour after this there arrived pinks, yellows, turquoise blue sky... the colours one typically associates with sunrise. Photos below taken at: 7:45am, 7:47am, 7:54am, 8:27am

Longhouse Bursary project

Shifting cloud cover at 7:30am during the period of Civil Twilight...