Venus in the daytime......

ankaragucu

Hi, I tried asking this before and got no replies.Hope no one thinks I'm taking the pi$$ but my query is about how to go about locating Venus in daylight?I dont mean early morning before/as the sun comes up.A couple summers ago out the back garden I was scanning the sky with my binos and was startled to happen upon what looked like a small golf ball.After a bit of googling I discovered Venus CAN be visible at this time of day (it was lunchtime) and figured thats what I must have been seeing.I lost it when some fluffy clouds drifted in and then couldnt re locate it.What I'm asking is, is there a website or an app that anyone knows of that gives times of year and info on position, etc as it would be great to know.
Cheers.

coylemj

Yes it's possible to find Jupiter and Venus in the daytime if you know where to look and (preferably) you stand in the shadows so that there is no risk of you accidently pointing your binos at the sun.

When they are at a safe angular distance from the sun, they will be visible either in morning or evening twilight so my advice to you would be to wait until the star charts show them as a morning or evening object and then plan on finding them in the daytime. In other words, if they are too close to the sun to be visible in the morning or evening, they are probably too close to the sun to be safely observed in the daytime.

Venus is at superior conjunction (directly opposite the sun) on June 6th so it can't be observed until mid July when it will make an appearance in the evening sky, it's in conjunction with Mercury on July 16th. For a daytime observation, I'd wait until the end of July onwards when it might be safe to go looking with the proper precautions and note that Venus will be in conjunction with Jupiter on August 27th.

Stellarium is a good piece of s/w to track the current position of the planets..... http://www.stellarium.org/

ankaragucu

Thanks coylemj.Needs a bit of figuring out so.I would have thought by now we'd have some kind of app for day time planet viewing complete with alerts and info for your geographic location much like the ISS tracker alert for night time passes of that object.Especially as it seems to me that an awful lot of folk wouldnt even be aware that they CAN be seen in the daytime and would in fact be quite interested in experiencing it.If there was a convenient and handy source to provide the guidance.Still I'll be on the lookout.
Thanks again.

coylemj

Venus is more often visible in the daytime than not and Jupiter is visible in the daytime for a considerable period each year so I can't see the need for a special app or getting alerts.

Venus is visible other than during the few weeks before and after superior conjunction (June 6th 2016) and inferior conjunction (March 25th 2017) when it's too close to the sun. It will be visible in the daytime and at a reasonable angular separation from the sun from the end of July 2016 to the beginning of February 2017 i.e. for seven consecutive months.

Jupiter was at opposition on March 8th, it currently rises at 13:00 and sets at 02:40 so is above the horizon in the afternoon. It will be in conjunction with the sun on Sept 26th so you will be able to find it in the daytime up to late August.

intheclouds

ankaragucu wrote: »

Thanks coylemj.Needs a bit of figuring out so.I would have thought by now we'd have some kind of app for day time planet viewing complete with alerts and info for your geographic location much like the ISS tracker alert for night time passes of that object.Especially as it seems to me that an awful lot of folk wouldnt even be aware that they CAN be seen in the daytime and would in fact be quite interested in experiencing it.If there was a convenient and handy source to provide the guidance.Still I'll be on the lookout.
Thanks again.

There probably is an app that does it - have you looked?

I googled and the very first item on the search was this:
http://www.skyandtelescope.com/astronomy-news/miss-a-sky-event-theres-an-app-for-that/

namloc1980

ankaragucu wrote: »

Thanks coylemj.Needs a bit of figuring out so.I would have thought by now we'd have some kind of app for day time planet viewing complete with alerts and info for your geographic location much like the ISS tracker alert for night time passes of that object.Especially as it seems to me that an awful lot of folk wouldnt even be aware that they CAN be seen in the daytime and would in fact be quite interested in experiencing it.If there was a convenient and handy source to provide the guidance.Still I'll be on the lookout.
Thanks again.

Stellarium will give you this info for any geographic location. Again you can't be too careful when observing in the daytime.

mickmackey1

On one occasion I saw it in daylight and it had a weird metallic glint, very UFO-like. And then on another occasion it just had a normal star-like appearance... maybe depends on the angle of the reflected sunlight.

jfSDAS

Hi ankaragucu,

The first pointer mentioned on the page http://www.funsci.com/fun3_en/sider/sider.htm is very similar to a device Sky & Telescope magazine sold a good few years ago. It allows you dial in the celestial coordinates of an object so the arrow points directly to it. The device is perfect for spotting Venus in the daytime. I haven't made one yet but it's on the to-do list!

John

ankaragucu

mickmackey1 wrote: »

On one occasion I saw it in daylight and it had a weird metallic glint, very UFO-like. And then on another occasion it just had a normal star-like appearance... maybe depends on the angle of the reflected sunlight.

Exactly Mickey, I thought I was looking at a UFO at first too!

ankaragucu

jfSDAS wrote: »

Hi ankaragucu,

The first pointer mentioned on the page http://www.funsci.com/fun3_en/sider/sider.htm is very similar to a device Sky & Telescope magazine sold a good few years ago. It allows you dial in the celestial coordinates of an object so the arrow points directly to it. The device is perfect for spotting Venus in the daytime. I haven't made one yet but it's on the to-do list!

John

Hi John and thanks for that.Would be great indeed but might be a bit too technical to build for a novice like me!Have a pair of 70 by 15 binos only.Next step for me is a decent telescope to be used with Stellarium and other info above.
Cheers again.

coylemj

mickmackey1 wrote: »

On one occasion I saw it in daylight and it had a weird metallic glint, very UFO-like. And then on another occasion it just had a normal star-like appearance... maybe depends on the angle of the reflected sunlight.

Venus is completely surrounded by dense clouds so the amount of sunlight it reflects is pretty constant. What you observed was probably as a result of the phases displayed by the planet, first discovered by Galileo.

When Venus reappears from behind the Sun at the end of June 2016, what you will see in a telescope is an almost 'full' Venus showing 99% of the disc illuminated by the Sun. As it will still be on the far side of the sun, it will be a relatively small object with a diameter of 10". From then until the end of 2016 the planet will continually rise in the evening sky and will be very prominent in the western sky after sunset. In a telescope the phase will be waning but as it will be getting closer to us, the reduction in visibility of the daylight side of the planet will be offset by it's increasing proximity to Earth so it won't vary much in brightness. In fact the biggest factor in it's visible brightness is it's angular separation from the Sun, once it clears a certain angle so it's visible 30 minutes and more after the sun sets, it will start to appear very bright because the background sky will be dark.

Now fast forward to January 12th 2017 when it will be at it's maximum angular separation from the Sun, known as greatest eastern elongation. Through a telescope you will see exactly half the disc illuminated so it will look like the First Quarter Moon. At that stage it will be a much larger object because it's closer to us than the sun and will show a diameter of 25".

It will reach it's maximum brightness on February 17th 2017 when the phase (visible % of the daylight side) will be 27% but the diameter will be almost 40".

So when you look at Venus though binos or a telescope, there is a large variation in what you will see - from a 99% illuminated disc with a diameter of 10" to a 27% phase with a diameter of 40" - four times greater. That variation caused by the phases of Venus is probably why you had different perceptions of what you were looking at rather than the amount of sunlight being reflected.

ps200306

jfSDAS wrote: »

Hi ankaragucu,

The first pointer mentioned on the page http://www.funsci.com/fun3_en/sider/sider.htm is very similar to a device Sky & Telescope magazine sold a good few years ago. It allows you dial in the celestial coordinates of an object so the arrow points directly to it. The device is perfect for spotting Venus in the daytime. I haven't made one yet but it's on the to-do list!

John

ankaragucu wrote: »

Hi John and thanks for that.Would be great indeed but might be a bit too technical to build for a novice like me!Have a pair of 70 by 15 binos only.Next step for me is a decent telescope to be used with Stellarium and other info above.
Cheers again.

The problem you will find is that the sky is a surprisingly big place, especially when trying to locate something that can only be seen with an optical aid. I watched Venus and Mercury one morning before sunrise, and then discovered (as you have) that I could continue to watch Venus with binoculars long after the sun was up. I finally lost track of it, not because it became invisible, but because I just couldn't locate it anymore after it rose too far above the gable of a house I was using as my "pointer". You can get the required location from Stellarium and other apps, but unless you have some means of pointing at it you're unlikely to just fall across Venus by accident, even with the 3-4 degree field of view that you probably have in your 15 x 70s.

ankaragucu

ps200306 wrote: »

The problem you will find is that the sky is a surprisingly big place, especially when trying to locate something that can only be seen with an optical aid. I watched Venus and Mercury one morning before sunrise, and then discovered (as you have) that I could continue to watch Venus with binoculars long after the sun was up. I finally lost track of it, not because it became invisible, but because I just couldn't locate it anymore after it rose too far above the gable of a house I was using as my "pointer". You can get the required location from Stellarium and other apps, but unless you have some means of pointing at it you're unlikely to just fall across Venus by accident, even with the 3-4 degree field of view that you probably have in your 15 x 70s.

ps200306, you are exactly right, it IS very difficult to spot and indeed KEEP spotted.As I said I caught it totally by accident when idly scanning the daytime sky with my binos.At first thought it was a ufo, then maybe a weather balloon but it just looked too high and somehow too solid.It was a beautiful day but when a few clouds drifted across it it was very difficult to re locate it.I eventually lost it altogether after about ten minutes even though the bit of cloud passed.
The reason I asked the initial question was that I know how thrilled I was to spot it and how unexpected it had been.I'm sure plenty of folk are totally unaware that it CAN be seen in the daytime and would love the opportunity, if they had the convenience of some sort of aid to guide them and help them.Thats all.

ps200306

Agree with that, ankaragucu ...it is quite an exciting spot. In fact I'm tempted to build that pointer thing myself, just for Venus spotting purposes. The other thing I've tried is calibrating landmarks at nighttime that can be used as pointers. The limitation is that, being on land, they tend to work best for low altitude targets. Here's one I did a few years back, using a combination of Google Maps and Stellarium to set up a neighbouring house as a pointer. In that instance I used it for repeat observations of Spica to demonstrate the length of the sidereal day as a student project, but it happens to be the same one I managed to use for Venus.