I would like to offer my congratulations to all SPA members who observed the early afternoon occultation of Venus by the Moon on June 18th. My thanks to all who contributed in any way.
Jon Harper
SPA Occultation Section Director
Many of the images in this report have been resized to fit within the space available, and in each case clicking anywhere over the image will display the higher resolution version.
John Abbeylands | Anthony Ayiomamitis | René Bourtembourg | John Carruthers | Mike Feist | Will Gater | Jon Harper | Tony Ireland | Peter Jones | Pam Jury | Pete Lawrence | Patrick Shepherd
The weather at the time of disappearance was total cloud cover, but the Met Office website (many thanks to Ian Hargreaves - letters page 31 of SPA magazine) suggested there might be some breaks in the cloud for the reappearance. Unfortunately it was cloudy right up to just before reappearance, so it was just not possible to set up my webcam and telescope as I had hoped. However, with my Canon 350, mounted on a tripod, I was able to get the following images with the standard type 200mm lens for the camera.
Thanks to pristine weather conditions earlier today, I had the privilege and thrill of observing and imaging my second occultation during the past three years involving two of the three brightest objects in the sky. In spite of the fact that the occultation of Venus by the 3.5-day old moon occurred during the day (similar to the May/2004 event), these two bright celestial bodies were easily visible both naked-eye as well as through the telescope's humble finderscope.
Venus is currently at 26.39 arc-seconds and growing as it approaches opposition later this summer. With a magnitude of -4.4 and a phase of 44.1%, it is an easy target to locate during the day and, particularly, when the moon is nearby so that proper focusing by our eye against the blue sky (for true infinity) becomes feasible. Through a telescope, even the telescope's finderscope, Venus and its approximate first-quarter phase are easily discernible.
Similarly, the 3.5-day old waxing moon was also a pleasant site through the telescope's finderscope with the thin crescent moon meticulously bathed against the rich blue sky. Its milky white surface allowed the identification of many major lunar features associated with the eastern quadrant, including Mare Crisium being the most dominant due to its proximity to the lunar terminator.
Please find attached three images depicting today's celestial waltz. The first attachment is Venus just to the east of the transparent lunar limb seconds before first contact and disappearance. Similarly, the second attachment is with Venus just past the western lunar limb seconds after reappearance, 80 minutes later. The third and final image is a collage of the first two images, which beautifully illustrate today's disappearance and reappearance.
More of Anthony's work can be found on his website.
Here in Belgium the whether was 3/4 clouded, but, by chance, I could see the disappearance and the reappearance of Venus between the clouds. The sight was wonderful! Venus was extremely bright compared to the Moon. I could see the planet with the naked eye in strong daylight (for the first time in my life). For the disappearance of the last part of the crescent, I obtained a timing of 14:11:06.2 UT, and for the reappearance of the limb I obtained a timing of 15:30:51.7 UT.
This image shows the reappearance of Venus at 15:24 UT. The image was captured afocally, via a 50mm binocular. I was clouded out for first contact, but it cleared in time for third. Visually it was just like the Apollo "Earthrise" images.
From Sussex the day started overcast, and by around mid-day it was raining and I did not even consider the possibility of seeing the occultation. Then I was struck down with visual disturbances associated with migraine, and so I took to bed and fell asleep. Some time before the occultation was due to start I was woken by Sandra, my wife, to tell me that the sky was miraculously clearing. The sky was deep blue between rushing clouds. The Moon was soon located using 12x50 optical aid, and then 8x42 binoculars. At about 2:48pm BST Venus was seen shining brilliantly off to the lower left of the crescent. I followed the lead up to disappearance as the two bodies seemed to be rushing together through the clouds. Then, at 3:03pm BST, Venus slowly faded out as it disappeared behind the invisible limb of the Moon. Then I waited until Venus popped out the other side at 4:22pm BST. In the 8x42 the Crescent Moon looked like a finger-ring, with Venus as the mounted diamond. I could not, however, see the planet without the binoculars. Incidentally this was my 215th observation of Venus in the daytime using small portable equipment.
I began setting up at about 13:30 local time. To my complete surprise, the clouds that had been covering most of South Devon that morning began to break up slowly. After waiting a while for gaps to move over the Moon, I was finally rewarded with my first glimpse of the occultation at 13:37 local time, when I imaged the first shot. I had hoped to image once every ten minutes and capture the whole event. The clouds had other ideas. From about 14:00 local time onwards it was a case of waiting for the right gap to come along to get the next shot. I missed the disappearance, unfortunately, which I had hoped to image close-up with a webcam. A few minutes before the reappearance the clouds suddenly revealed the Moon, and I was able to catch Venus popping out from behind the Moon.
Here are my two images from the event. I had intended to use the webcam for it, but in the end went back to the trusty old 300D. There's a progression sequence showing Venus approach the Moon and then hide and reappear, as well as a widefield with some of the clouds that were playing havoc with my focusing and exposure settings!
More of Will's work can be found on his website.
Three members of Scarborough and Ryedale Astronomical Society met at the Holbeck Clock Tower on the esplanade in order to observe the occultation and to allow members of the public to look through various instruments at the occultation. However for the third consecutive week sea mist from the North Sea obscured everything, even the sun could hardly break through! Needless to say, the immersion of the planet came and went without a single sighting of the moon. We knew that 800 metres to the west, away from the sea front, the skies were clear with just a small hint of Cirrus in places. So at 3.45pm BST, we decided to pack up and go to our respective homes in order to observe the emersion of Venus if we could.
Under a beautifully clear sky from my backyard in Scarborough, I set up my 9" Dobsonion mounted f/6 Newtonian reflector, and got my gear together for timing the 3rd and 4th contacts of the planet's disc at emersion. I also had to hand my Canon Ixus 300 camera. At third contact the planet burst into view like an atomic explosion, its cloud bound atmosphere reflecting far more sunlight than the moon ever can. A most magical moment! -- but then, what do you expect, I simply LOVE occultations!
It was delightful, afterwards, to see clearly, as I pointed out in the notes we've distributed about this event, the planet in full daylight with the naked eye. All in all this has been, in my opinion, perhaps the most beautiful occultation of the year.
The timings of 3rd and 4th contact from my geographical co-ordinates were as follows:
Lat:N 54° 16' 29.7" Long: W 00° 24' 59.1" Ht: 50 m (Datum: WGS84)
18/06/2007 EMERSION of VENUS
Third Contact (start of the planets appearance):15h 19m 01.76s UT (Reaction time of 0.8 secs deducted)
Fourth Contact (estimated last contact with the planet's unilluminated dark limb): 16h 20m 03.09s UT
Time for complete emersion: 01 minute, 01.33 seconds which is consistent with the PA of emergence and a planetary disc of 26 seconds of arc.
The two images were taken with the Canon digital camera. The first shows the moon and Venus several minutes after emersion. The camera was hand-held at the 15mm orthoscopic eyepiece. The second shows the naked eye appearance of the two objects at 16h00 UT and the top of my Silver Birch tree!
I still have my trusty (basic) ETX 90 with which I have taken many astro-photographs of the Moon using a Fuji 700 digital camera hand-held to the eyepiece. I got some decent photographs of the Saturn conjunctions this year, though I do not have the skill to process them to produce some of the amazing images that have appeared in our astronomy magazines. However, this afternoon I was able to image the close approach of Venus and the Moon, finding your notes a great help in picking up the Moon and Venus easily, with the Sun hidden by the house. Sadly there was heavy cloud throughout the occultation - about an inch of rain fell in less than an hour - but by 5:00pm the sky cleared and, rushing back from shopping, I set up the ETX 90 and snapped the attached image - plus several others, before the cloud came over again.
The attached photo was taken at 16.05 UT, with an exposure time of 1/250 at f/4.0, using a 20mm lens. I have processed the image, to try and improve the contrast. I have ALWAYS wanted to take a photograph like this, to compare Venus with the Moon - at last I have done it!
I couldn't believe my luck on Monday. There had been total cloud cover all morning, but, ever the optimist, I put the telescope out at 13.45 BST and within 10 minutes patches of blue sky started to appear. The cloud cover quickly broke up to leave white fluffy clouds that were moving across at speed in a strong wind, and patches of thinner high cloud that were slow moving. As soon as I spotted the Moon, Venus was clearly visible, very bright, in fact brighter than the Moon. A fine sight! Incredibly I had a window of blue sky for about 5 minutes just before and during immersion, and another for about 30 minutes 2 minutes before Venus reappeared. I found this occultation more difficult than that of Saturn for two reasons. Firstly, the wind was so strong that it moved the telescope, and secondly because the Sun was so bright that it was almost impossible to see the view screen on the camera. I couldn't tell if the camera was centred on the eyepiece, or if the image was centred in the field of view. It was a case of click and hope. Having said that, I think I managed to get quite a nice sequence of the emersion, although the shots of immersion aren't as good. I used a Kodak digital camera held to the eyepiece of 12" Dobsonian, giving a magnification of 166x. I tried using the zoom on the camera for some shots. This gave a larger image, but at the expense of definition. Another great event to watch.
Immersion
Emersion
I saw part of this event at Brighton Marina, in Sussex, with a 10 x 50 binocular - though I barely needed the binocular. I first saw the approach around 1/4 degree from the Moon, about 3:00pm but, searching for a better vantage point and with clouds around, managed to miss the disappearance. So I patiently waited over a glass of wine for the reappearance. I was delighted when, around 4.25pm, I caught sight of Venus popping out from the bright side, looking a bit like the stem end of an orange to start with. It had been touch and go for a while, because of intermittent clouds, which threatened to hide the interesting bit of the viewing, but they cleared in time.
Pete submitted the following image to the SPA Gallery Forum:
More of Pete's work can be found on his website.
Thanks to fortuitous breaks in the cloud, the daylight occultation of Venus was clearly observed with binoculars. Best estimates of DD 14:00:40 UT and of RB 15:17:00 UT. My position (by Garmin SatNAv) 50° 19' 05"N, 002° 16' 05"W (Approximately 1 mile North of Portland Bill). Thanks to SPA for alerting me to this spectacular sight.
