Venus in Daytime!

[Outbackmanyep]

Hi all,
I have just been out observing Venus in broad daylight with the 7x50 Bins and you can make out the crescent shape easily.
Now's a good time to catch Venus at a whopping 50", it's an awesome sight in the 8" SCT.
It's about 17 degrees North of the Sun and 23 degrees to the East of the Sun.
Cheers! :D :thumbsup:

[ngcles]

Hi Chris & All,

Good stuff Chris. :thumbsup::thumbsup:

Has anyone been able to "resolve" the crescent shape naked-eye?

I've never done it with certainty (I thought I'd perhaps seen it a couple of times in the past but can't be 100% certain). There are reports of being able to see a crescent when near maximum angular size that date back millenia. Young eyes are apparently a decided advantage.

If you've got a clear western horizon tonight and with Venus at its largest angular diameter why not give it a go or alternately try in the morning in a few weeks time.


Best,

Les D

[Outbackmanyep]

Hi Les,
I wasn't able to see it crescent shaped but i could see it naked eye around 2:30pm today.

[Enchilada]

I mostly doubt it. The maximum size is 1 arcmin (61 arcsec), which is about half the resolution of the naked eye. However, I only once (from about 9 attempts) thought I saw the crescent in the morning eastern sky just before sun-up - on the final day Venus was possibly visible. The eye saw what instead looked like two stars on the opposing cusps, though I could not see the crescent. In binoculars, the crescent was obvious, whose phase was about around 1%. Sadly, I had about one and a bit minutes before in was lost in the general haze caused by the solar rays just reaching the lower atmosphere. I did not earlier see Venus on the western side due to cloud cover and heavy rain (earliest I think was about 3% or 4%). Robert Price when he was in Cootamundra observed the crescent several times too - but the observation was either binoculars or telescopes.
A recommended trick is said to use a purple 35A Wratten filter, which darkens the field and improves contrast. It had something to do with the ultra-violet emission of the upper atmosphere of Venus - but for me it made minor differences. I eventually convinced myself it was simply bull from formal UV observations by one of the old Venus orbiter missions.

I'll dig up my notes and comments tomorrow, and look up my general text of Venus - but for now - I'm off to bed. I've got a drawing in my note book too. (Earlier really a terrible night's observing except for the widest of pairs - mixed with the moonlight. Yucky poo!)

Hope you guys did have some luck spotting the narrow crescent.

NOTE: In the old days I use to do drawings and visual observations of dichotomy for the B.A.A. Mercury and Venus section. Observations were made in daylight on the meridian, which was really punishing in the summer months. The practice of seeing the maximum crescent in daylight was considered to be too dangerous so near the Sun.

[Enchilada]

Added comment.

The best time to look before sunup or after sunset for the thinnest c.2% crescent is the 21st and 22nd March and the 2nd and 3rd April. (West and East respectively)

IMPORTANT CAUTIONARY NOTE

I would suggest visual observation near the sun during daylight is very dangerous without adequate shielding from the sun's ray.
(Between about the 12th March to 6th April,
unless you are experienced, NO ONE SHOULD TRY IT!)


If you REALLY WANT TO DO IT, use an eye patch to stop glimpsing the sun as its brightness I has the bedazzling you seeing much let alone Venus - probably buggers up your deep-sky observing if you do it too long!

[Enchilada]

Suggest you read the article at;
http://homepage.mac.com/andjames/PageVenus002.htm

Ephemeris
http://homepage.mac.com/andjames/PageVenus007.htm

The last paragraph talks about the Ashen Light (seen it once or twice), prevalent during the thinnest of crescents.

Cheers
Encha

(I'll do an ephemeris based on times near sunup and sunset, so you can know the exact time, elevation, phase and elongation.)