OASI: ToV

The second and final transit of Venus of the 21^st Century took place on Wednesday 06 June 2012. It began shortly after 22:00 UT on the previous day and fourth contact, from Ipswich, was forecast for 04:54:54 UT. Sunrise was at 03:38 UT, therefore, weather permitting, the final hour and a quarter or so of the event would be visible from East Anglia.

OASI's preparations for the 2012 transit began some weeks in advance of the event. Most prospective observers intended to observe from Orwell Park, and there was a ready consensus among them to use the Tomline Refractor to project a large image of the Sun for viewing and for taking photographs and videos, and to supplement this with the Coronado PST (Personal Solar Telescope) mounted on the roof of the transit chamber, for direct viewing by dedicated (foolhardy?) observers. Only one of the balconies off the Belvedere was positioned to enable observation of the transit, and Bill Barton proposed to set up his Hα telescope there to offer another, more easily accessible, direct view of the event.

Building on the experience of the 2003 transit of Mercury and the 2004 transit of Venus, Martin Cook and I aimed to extend the camera platform at the eyepiece end of the Tomline Refractor to accommodate one video camera and two remote-controlled stills cameras, all mounted close to the optical axis of the telescope. Martin fabricated the necessary metalwork and a trial run demonstrated that, with a little jostling for position, it could support three cameras. There was considerable discussion over whether OASI should buy an HD video camera for use during the transit. The Treasurer authorised the purchase (thanks, Paul!) but in the end I concluded that this was an extravagance too far, and we settled instead on using a rather ancient mini-DV model (from which videos can be streamed to a PC for easy distribution).

With one week to go to the transit, we rigged the sunshade across the aperture of the dome, attached the projection screen to the Tomline Refractor and tested the cameras in situ. To capture the Sun rising, the Tomline Refractor would need to point slightly downwards, resulting in the projection screen being raised to a height of some 2.5 m above the floor of the dome. For ease of viewing, we built a 1.5 m high viewing platform from a scaffolding tower, and made provision to display the feed from the video camera on a large monitor mounted at table-top height.

The weather forecast for the day of the transit was very unfavourable: largely rain and dense cloud with only a very small chance of a few brief clear intervals towards the end of the event. However, in view of the significance of the event and the interest in it, Martin and I had committed to open the Observatory whatever the weather, and 22 members of OASI registered an interest in observing from Orwell Park.

On the day of the transit, Martin and I arrived at the Observatory at 3.30am, under dense cloud and some light rain. After a brief discussion over whether, in view of the weather, it was worth completing final preparations for observing, we decided to press ahead in case the skies miraculously cleared. At 4.00am, preparations almost complete, I went downstairs to meet the other prospective observers and escort them upstairs to the dome. Expecting the weather to have discouraged most intending observers, I anticipated finding no more than two people, but on rounding the corner into the car park, found instead a group of 16 posing for a photo amid a hubbub of conversation!

All the observers made their way from the car park to the Observatory, most settling in the dome. Martin and I commandeered the balcony with a prospective view of sunrise, searching constantly for any potential gap in the clouds. Bill had decided after all not to attend the observatory with his Hα telescope, so the balcony was empty; this enabled us to pick a dainty path through the centimetre or so of standing water there (deposited overnight thanks to Anglian Water's recent declaration of The 2012 Suffolk Drought). From the balcony, we accumulated a fine set of photos of dense cloud and mist. A brief flurry of excitement ensued at about 5.00am when Martin spotted a young deer on the land between Orwell Park and Levington Road: we attempted to image the creature but it was occulted by undergrowth before we could fire up a camera. Meanwhile, the thwarted observers in the dome consoled themselves by watching live Internet video feeds of the transit of Venus (from locations with less cloud cover than Orwell Park!)

Shortly before 6.00am, around the time of fourth contact, skies were still completely overcast. We gave up any notion of observing, and gathered everyone upstairs in the dome for group photos. There were many new cameras that people weren't confident in working, so there was much fumbling with controls and cursing under the breath. After the photos, most people dispersed, leaving Martin, John, Joe and me to dismantle the equipment and restore the dome to its usual condition; this we quickly achieved.

We looked out at the sky before locking the Belvedere, and found that the cloud cover was easing slightly. Shortly thereafter, in the car park, a further brief thinning of the cloud enabled the Sun to cast intense shadows against the wall of the gym. But the sunshine lasted only intermittently thereafter throughout the remainder of morning.

Thwarted observers at Orwell Park on 06 June 2012 were, in alphabetical order: Merlyn and Roy Adams, James Appleton, Martin Cook, Adrian Cubitt, Aisha and Janice Gilbert, Tina Hammond, Matthew Leeks, Michael Norris, Lindsay Smith, Joe Startin, B. Thompson, John Wainwright, Scott Wheatley, Paul Whiting, Mike Whybray and Jennie Wood. Reports of the 2004 transit may be found at: www.oasi.org.uk/Obsvns/20040608_ToV.php: they illustrate the full extent of what the would-be observers missed in 2012.

Meanwhile, Alan Smith, Roy Gooding and Eric Sims intended to observe the transit from the eastern side of Felixstowe, which offered a clear horizon over the North Sea. A week and a half before the transit, while reconnoitring potential locations, Alan saw a sun pillar shortly after sunrise and captured the scene on his phone camera. Needless to say, due to the weather, none of the three attempted observations on 06 June.

Further afield, Neil Morley hoped to observe from Tarrant Keyneston in Dorset. Unfortunately, at sunrise there was heavy rain which finally stopped around 5.00am leaving a lot of low cloud. There were fleeting moments of brightness, but not enough to observe the sun properly. At the time of 3^rd and 4^th contact, there was 100% cloud cover.

Mike O'Mahony wins the prize for farthest-flung observing location. He was on holiday camping in the deserts of New Mexico, USA during the time of the transit, and had brought his 15x50 monocular together with solar filter to observe the event. Picking a very remote spot on the map between Santa Fe and Albuquerque, which he thought would be free of both clouds and people (elevation about 2100 metres), he arrived at the location to find to his surprise that a local astronomy club Rio Rancho Astronomical Society, www.rrastro.org was already in place with about 10 telescopes, including Schmidt-Cassegrains, Dobsonians and refractors. Best of all they had lots of cold drinks in the cool box! Mike observed from the start of the transit through to sunset at 8.00pm local time, in the company of his newly-found colleagues, taking several photos shown below. He observed the teardrop effect on ingress through a 28 cm Celestron belonging to the Rio Rancho astronomers. had the weather been kind at Orwell Park, the observers there would have observed a continuation of Mike's observations, sunset in New Mexico occurring at 4.00am UK time.

Sun pillar a week and a half before the transit. (Alan Smith.)