Re: Transit of Venus
Sara, 1) That is pretty original. 2) It won't be copied by anyone in our lifetime. -Bill "Ken Launie, proposed to me between first and second contact of Venus on the Sun as we shared an eyepiece" --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Eclipse shades
We grabbed the clan and popped over to the big island for the transit. Stayed in Waikoloa. I had bought a good quantity of large #14 welding filters for what was a recent partial eclipse in our area. Brought those along and a 50 mm spotting scope for projection. My son-in-law, he of the 20-10 vision (uncorrected, lucky SOB), could watch the whole thing through a #14 filter. The rest of us had trouble until an hour or so before third contact, when the sun was lower, at which time I conjecture the additional absorption of the atmosphere brought the light level down to where Venus was also obvious to the rest of us. We had paper solar sunglasses with NASA's logo on them, but I don't know if anyone used them and so can't report on them. The spotting scope worked like a charm. At noon, clouds started to come into the Waikoloa area so we scanned the skies and raced half way down to Kona airport and set up in a lava field in plenty of time (2 minutes early). No clouds for miles. However, we had an uneven wind. The wind blew dirt onto our projection screen and made the setup tremble. Visually, we could see plenty of detail in the sunspots on the screen, but the vibration made it impossible to shoot a sharp picture of the projected image. Not too much is lost in the greatly reduced size image attached. The reason the image is blue is that the annular disc of cardboard we put on the telescope for a shade allowed blue sky light to fill in the dark shadows on the screen. I could color correct, but I thought you might find that interesting. To the naked eye, the shadows were not blue and the vibration wasn't a problem. The human eye-brain system is good equipment. John Bercovitz What Dick said Tue, Jun 12, 2012 4:34 am: The commonly stated resolution of the eye is about a minute of arc. The angular size of Venus during the transit was just under a minute of arc, so it would have been a difficult observation under any circumstances. A minute of arc is about 1 inch at 100 yards, i.e. an American 25 cent piece at the end of an American football field. <>--- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Eclipse shades
The commonly stated resolution of the eye is about a minute of arc. The angular size of Venus during the transit was just under a minute of arc, so it would have been a difficult observation under any circumstances. A minute of arc is about 1 inch at 100 yards, i.e. an American 25 cent piece at the end of an American football field. --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Eclipse shades
Your images are beautiful, Anne. I love the tatted Sun! Thank you, Maureen On Jun 11, 2012, at 10:50 PM, Bruvold Anne wrote: > I saw the Venus transit 8 years ago using Eclipse shades, but found it harder > to spot it this year – but then my eyes are 8 years older and my glasses a > bit stronger and thus decreasing the image a bit more than the glasses I used > 8 years ago. > > I was happy to observe the entire transit from Tromsø at the top of Europe. > The second contact was about 20 minutes before the sun was due North, and the > lovely weather lasted all the night, only after the transit the clouds came. > > Photos here: http://flic.kr/s/aHsjzM4MdT > > Best > Anne Bruvold > Tromsø > Norway > > From: sundial-boun...@uni-koeln.de [mailto:sundial-boun...@uni-koeln.de] On > Behalf Of Astrovisuals > Sent: 12. juni 2012 08:49 > To: sundial@uni-koeln.de > Subject: Eclipse shades > > I imported 5000 copies of the Eclipse shades from Rainbow Symphony, mainly > for the total solar eclipse in November, and they sold out very quickly for > the transit! > Was a bit surprised and concerned that, as Roderick found, Venus would be > very difficult to see with the naked eye. > > So was relieved to be able to see Venus with the shades, but only when it was > away from the edge of the Sun, where it was very hard to see. > There was a bit of a debate amongst us as to whether it would be visible > naked eye, but think it depends on how good your eyes are! > > And here is my version of a famous cartoon by local artist Michael Leunig, > for those who said it was just as good online! > > https://www.facebook.com/#!/photo.php?fbid=3380930736336&set=a.1430170488549.2054191.1661470374&type=1&theater > > Cheers, > > * David Widdowson, ASTROVISUALS, * > EMAIL: mailto:m...@astrovisuals.com.au > WEB: http://www.astrovisuals.com.au/ > --- > https://lists.uni-koeln.de/mailman/listinfo/sundial > --- https://lists.uni-koeln.de/mailman/listinfo/sundial
