Seeing Jupiter in Daylight

[ian musgrave]

I saw Jupiter in daylight with the unaided eye today. Well, sort of daylight, it was 11 minutes before sunset, with the Sun only 2 degrees above the horizon, and well hidden behind houses and trees, with Jupiter on the other side of the Sky. I had also planned carefully, and organised a vantage point with a pole that I had lined up with Jupiter on previous occasions before Sunset. Still I was surprised at how easy Jupiter was to see.

So what is the earliest you can see Jupiter in the daytime with the unaided eye? I found an article from 1917 (http://articles.adsabs.harvard.edu/full/1917PA.....25...31R) that says you can see Jupiter only when the Sun is 5 degrees or less above the horizon. The Sun is 5 degrees above the horizon around 30 minutes before Sunset now at my location (and Jupiter 43 degrees above the horizon). So I will have a go at it on the weekend if the weather is kind.

Has anyone else had experience seeing Jupiter in the daylight with the unaided eye?

[jjjnettie]

Well spotted!

[Blue Skies]

Yes, I've seen Jupiter during daylight a number of times. There were a series of weeks one year I was able to watch it about 20 min after sunrise in the morning sky - it was the place I was living in at the time, it nicely blocked the sun right out!

But even better was seeing Jupiter during a mid-morning daytime occultation. Having the moon nearby definitely helps, as it does for Venus. Jupiter was a bit of stretch without the moon to help but it was do-able once I knew where it was. The moon and Jupiter were about 45 deg high in the west at the time (was early Jan 2005 if I remember right...)

Sirius would be the next challenge, I haven't managed that one yet!

[ngcles]

Hi Ian & All,

Interesting question Ian.

Yep I've seen Jupiter many times during the daytime -- the trick is knowing *precisely* where to look. Having the Moon close-by makes it somewhat easier as others have noted. The Moon serves both as a marker and also to get your eyes focused at infinity.

If you have a telescope with accurately aligned DSC in daytime, slew to Jupiter (you can see Jupiter easily in any telescope in the daytime). It is pretty simple to see Jupiter then in the finder. Once you have done that, try and then sight along the top of the finder with the unaided eye. I've seen it dozens of times in the middle of the day in this way -- most often from Sydney Observatory. It is easiest when Jupiter is 90 degrees from the Sun in the polarised zone of the sky.

I've also spotted Sirius and Alpha Centauri using a similar method at times up to an hour before the Sun sets (ie when it is fairly low on the horizon). These two and Canopus are easy to see through the telescope during the day.

Best,

Les D

[OneOfOne]

You should have a go at Venus in a few more weeks when it get a bit higher in the evenings...a magnitude or two brighter makes a lot of difference.

Always wondered how the heavens would have been explained if some of it was easily visible through the day...

[Outbackmanyep]

Yes i have!
It was a couple of years ago when the moon was within 10 or so arc mins from Jupiter, the moon was first quarter and you could see it naked eye then!

[hector]

I have caught Jupiter 3 times in daylight, my best being last year at about an hour after sunrise. Jupiter was positioned just a few degree's north of Jupiter not long after opposition. The other times were only 15-20 minutes after sunrise< no luck with evening observations.
Andrew

[StephenM]

Daytime Antares

Hi all,
After reading this thread a couple of weeks ago, I decided to have a go at Antares (mag 1) today while the moon was close. It was very easy in my 130mm Newtonian at 2:30 pm this afternoon, but despite several minutes trying, I could not pick it up using 10x50 binoculars. It was interesting to see how red it appears against a bright sky - I guess due to the reduced contrast. Only the second star I've seen during the day (the other being the sun of course), so I'm glad I took the scope out!

Cheers,
Stephen

[MrB]

Not had a go at Jupiter yet, might try it.
Hunted down Venus some time back. Took me a while but got it. The most interesting thing for me was that after finding it, I could look away for a while and then find it again within seconds using no visual references (moon, roofline/corner of building etc).

It's pretty common for radio-controlled aircraft pilots to spot stars and planets during the day.
As they are following their plane, with eye's pretty closely focused at infinity, they often see stars gently drift past their planes :)