Venus in the Daytime

With the Moon only a half a degree from Venus this morning, it should be relatively easy to spot the brilliant planet high in the daytime sky.

Crescent Venus
Venus approaching inferior conjunction, 24Dec2013

Spotting planets in the daytime is not that difficult, both Jupiter and Venus are bright enough to seen in full daylight. Venus is currently near maximum brilliance at about -4.3 magnitude, easily bright enough to see in a clear sky. There are a few helpful hints to make this easier.

Today the Moon will make finding Venus quite easy. The planet is only half a degree above the Moon, just above the slim crescent.  Keep in mind that the Moon is half a degree across, the planet will be half a Moon diameter above the unlit side, easy to spot in the mid-morning sky.  Having the Moon nearby will not only aid in locating the Planet, it will also provide your eyes something to focus on.

Venus in the Daytime

With the Moon only a few degrees from Venus this afternoon, it should be relatively easy to spot the brilliant planet long before sunset.

Venus 28May2012
Venus photographed on 28May2012, about 13° from the Sun in the mid-afternoon sky
Spotting planets in the daytime is not that difficult, both Jupiter and Venus are bright enough to seen in full daylight. Venus is currently near maximum brilliance at about -4.6 magnitude, easily bright enough to see in a clear sky. There are a few helpful hints to make this easier.

Today the Moon will aid finding Venus in the sky as it is about 5° north of the Moon. Having the Moon nearby will not only aid in locating the Planet, it will also provide your eyes something to focus on.

Of course these bright objects will be even more dramatic after sunset when Mars will also be visible nearby.

Seeing Planets in the Daytime Sky

We expect to wait until darkness falls to observe the stars and planets. While the Sun and Moon are normally seen in the daytime sky, there are other objects that may be observed.

Crescent Venus
Venus approaching inferior conjunction, 24Dec2013

Both Jupiter and Venus are bright enough to see fairly easily in full daylight if conditions are right. Saturn can be observed with a telescope if you can locate it. Very occasionally, we are treated to a daytime visible comet.

Jupiter and Venus are the easiest, you simply need to know where and how to look, but once glimpsed they are fairly easily seen. It is the knowing how that makes it possible. Try these simple hints…

  • Try when the planets are far from the glare of the Sun, in the first hours after dawn or last hours of the day are best.
  • Clean air is necessary. If the air is hazy, dusty or smoggy it will hide the planets from view, particularly when near the Sun. There will just be too much solar glare to pick out the planet. For the same reason try when the planet is high in the sky and you are looking through much less air.
  • The human eye will relax and defocus if there is nothing to focus on. This happens when looking at a plain expanse of blue sky. You could be looking right at the planet and not see it. A few puffy clouds around, or better yet, the Moon, will give the eye something to focus on, allowing the planet to be easily seen.
  • Put the Sun out of sight to reduce glare. Simply position yourself in the shadow of a tree or building to get a better view.
  • Pick a day when the Moon is near the object you are looking for, it will provide a simple signpost to the correct location.

It is this last hint that can be particularly useful. Looking ahead with the aid of a planetarium program you can find a day when the Moon is near the planet. Using the program to estimate the position with respect to the Moon you can look in just the right place. If you get it right the planet will appear as a bright star-like object. Once you see it you will wonder how you ever missed it in the first place.

Have a try.

Seeing Venus in the Daytime

It is possible to see planets in the daytime. Both Jupiter and Venus are bright enough to see fairly easily in full daylight if conditions are right. You need to know where and how to look, but once glimpsed they are fairly easily seen. It is the knowing how that makes it possible. Try these simple hints…

  • Try when the planets are far from the glare of the Sun, in the first hours after dawn or last hours of the day are best.
  • Clean air is necessary. If the air is hazy, dusty or smoggy it will hide the planets from view, particularly when near the Sun. There will just be too much solar glare to pick out the planet. For the same reason try when the planet is high in the sky and you are looking through much less air.
  • The human eye will relax and defocus if there is nothing to focus on. This happens when looking at a plain expanse of blue sky. You could be looking right at the planet and not see it. A few puffy clouds around, or better yet, the Moon, will give the eye something to focus on, allowing the planet to be easily seen.
  • Put the Sun out of sight to reduce glare. Simply position yourself in the shadow of a tree or building to get a better view.
  • Pick a day when the Moon is near the object you are looking for, it will provide a simple signpost to the correct location.

It is this last hint that can be particularly useful today. Venus is about 8° degrees south of the Moon today. It helps that Venus is near maximum elongation, as far as it will get from the Sun for this evening apparition. If you can find the Moon high in the midday sky check just below it for Venus. The planet will be about a sixteen lunar diameters away from the Moon, seen as a bright star-like object.

Have a try.

Venus Approaching Transit

As we approach the Transit of Venus I decided to attempt to photograph Venus as a very thin crescent. I do not normally pay much attention to the planet, it is pretty when seen in the sunset. But when you turn a telescope to Venus it is quite boring, a white ball with no detail to be seen. I find I have been paying a bit more attention with the transit looming close on the calendar.

I could photograph the planet after sunset, but as Venus is quite near the Sun it would be very low in the sky and I would be shooting through a lot of air to get the imagery. Atmospheric distortion would be a major problem. The other method is to try something I had not done before, photograph the planet in the daytime, high in the sky and quite near the Sun.

Imaging Venus in the Daytime
Imaging Venus in the daytime a mere 12°44' from the Sun.
Don’t try this at home?

Yeah, This will be a tricky operation. Venus will be only 12°44′ from the Sun, meaning I will have to be quite careful to avoid roasting my equipment, or my eyes.

I chose to use the 90mm APO refractor. With the optics at the front there will be some sunlight splashed down the interior of the tube. It should not be a focused image as it will hit the tube not even halfway down. There the heavy aluminum tube walls should dissipate the heat efficiently. The fully baffled tube should also stop much of this light before it reaches the camera. I may not have designed and built the optical tube with this sort of abuse in mind, but I did build it heavy, it will take it.

Venus 28May2012
Venus on 28May2012, about 12°44' from the Sun
I located Venus by centering the Sun with the solar filter on the ‘scope. I then adjusted the setting circles and offset to the correct coordinates for Venus. After a visual safety check I removed the solar filter for a look. And there it was, a graceful and very thin crescent shining brightly against the blue sky. Replacing the eyepiece with a camera I focused and shot several video sequences.

The results? The final image can bee seen to the left. Not horrible, but it could have been better. The seeing at 11am was already starting to degrade, I am always amazed at how well the software can extract a half decent image from such distorted original material. The magic of sorting through and averaging a thousand frames. I wonder what I could do with better seeing.

Another try? Probably not, Venus is quickly getting closer to the Sun as we approach transit in nine days. The next time I photograph Venus it will most likely be silhouetted against the solar disk. Maybe an attempt after transit? I could shoot earlier in the morning with possibly better seeing.

Finding Venus in the Daytime

It is possible to see planets in the daytime. Both Jupiter and Venus are bright enough to see fairly easily in full daylight if conditions are right. You need to know where and how to look, but once glimpsed they are fairly easily seen. It is the knowing how that makes it possible. Try these simple hints…

  • Try when the planets are far from the glare of the Sun, in the first hours after dawn or last hours of the day are best.
  • Clean air is necessary. If the air is hazy, dusty or smoggy it will hide the planets from view, particularly when near the Sun. There will just be too much solar glare to pick out the planet. For the same reason try when the planet is high in the sky and you are looking through much less air.
  • The human eye will relax and defocus if there is nothing to focus on. This happens when looking at a plain expanse of blue sky. You could be looking right at the planet and not see it. A few puffy clouds around, or better yet, the Moon, will give the eye something to focus on, allowing the planet to be easily seen.
  • Put the Sun out of sight to reduce glare. Simply position yourself in the shadow of a tree or building to get a better view.
  • Pick a day when the Moon is near the object you are looking for, it will provide a simple signpost to the correct location.

It is this last hint that can be particularly useful today. Venus is about 4° degrees south of the Moon this afternoon. If you can find the Moon in the late afternoon check just below it and to the left for Venus. The planet will be about a eight lunar diameters away from the Moon, seen as a bright star-like object. Tomorrow it will be Jupiter’s turn, and you can try again to see a planet in the daytime.

Have a try.

Comet Lovejoy in the Daylight

I did attempt to see comet C/2011 W3 Lovejoy in the daylight. I actually tried several times. Once on the morning of the 15th and a couple more times on the morning of the 16th after I heard that the comet had survived perihelion passage. Neither time did I see the comet with an unaided eye.

On the 15th I was not surprised I could not see it. I was in Waimea where there was a lot of low altitude haze and a lot of glare around the Sun. On the 16th I had a much better chance using the clean high altitude air of the summit of Mauna Kea. But still, no comet seen even though it should be just over four degrees from the Sun. This is about the same separation that had allowed me to see comet McNaught in early 2007.

Just to be certain I set the camera on a tripod, placed it just inside the shadow of the Keck 1 dome, and blazed away. Examining the photos on the camera display likewise revealed no trace of the comet, but there were some interesting spots of light.

It was not until I sat down and really analyzed the raw frames that I found something. Using some astronomy software, I calculated the position of the comet when the shots were taken and the field of view of the camera. And lo! There it was, a small spot with a trace of tail. It showed up best in the green channel, and not at all in the blue thanks to Rayleigh scattering in our atmosphere. Stacking nine of ten frames and processing the heck out of the frames does allow you to clearly see the comet…

Comet C/2011 W3 Lovejoy
Comet C/2011 W3 Lovejoy photographed 4° from the Sun on at 19:47UT on the morning of 16Dec2011. Canon 60D and an 85mm lens, stack of nine frames, green channel only.

Daytime Comet Reminder

Will Comet C/2011 W3 Lovejoy be visible in the daytime? This is the morning to find out. Look about 2° below the rising Sun once it is well up in the clear sky for a small white object. Two degrees is four times the Sun’s width in the sky.

C2006/P1 McNaught
C2006/P1 McNaught photographed five degrees from the Sun, stack of three images
If the comet is not visible to the eye, it should be spectacularly visible in the imagery sent back by one of our solar monitoring satellites. Check out the SOHO page for the latest imagery. The comet should have entered the field of view of the LASCO C3 instrument early on Dec 14th (late on the 13th HST) and well in by the time this posts. If the comet does not survive perihelion passage, this is one of the best views of the event.

I have seen one other daytime comet in my life, C2006/P1 McNaught back in January of 2007. That time the comet was about 5° from the Sun, over twice as far away from the glare. The photo at the right should give an idea of what to look for today. Remember to shield your eyes from the Sun’s glare by positioning yourself to put the Sun behind some object like a wall or streetlight. There is no guarantee that Lovejoy will be at all visible, but it is worth taking a look this morning.

A Daytime Comet?

The rumor is running around the various astronomy sites and listservers that Comet C/2011 W3 Lovejoy might be daytime visible. Will it be? That is a very qualified maybe.

C2006/P1 McNaught
C2006/P1 McNaught photographed five degrees from the Sun, stack of three images
This sun-grazer comet was discovered just a few days ago, on November 27th, by Australian amateur astronomer Terry Lovejoy. The comet is a member of the Kreutz comet family, and like other members of the family it will approach the Sun quite closely, about 548,000 miles (882,000 km) from the Sun. Of course those distances are solar centric distances. Taking the radius of the Sun into account means that the comet will be a mere 115,000 miles (186,000 km) above the photosphere, hot indeed!

It becomes a valid question to ask if comet Lovejoy will even survive perihelion transit.

Passing that close to the Sun will mean that the volatile elements of the comet will be streaming off the comet at a fantastic rate, enough to dramatically brighten the comet. Below you will find the ephemeris for perihelion on Dec 16th (Dec 15th HST) from the Minor Planet Center. As you can note, the predicted magnitude is -8! This is bright enough to be seen in broad daylight. Thus the possibility of a daytime comet.

The catch is that the comet will be quite close to the Sun. Within 2° as the Sun and comet rise on the morning of the 15th here in Hawai’i. For observers in the islands the best chance to look is on the morning of the 15th, as perihelion will occur in the afternoon as the comet passed behind the Sun from our point of view.

Will it be visible? Maybe. It depends on the accuracy of the magnitude estimates, which are uncertain to say the least. It could be substantially dimmer, or even substantially brighter than forecast under such conditions. The proximity to the Sun also complicates the issue. It is worth a look, seeing a daytime comet is highly unusual.

If you do look please take a few simple precautions… Do NOT use any sort of optical aid this close to the Sun, the risk of permanent eye damage is too great. If it is bright enough the comet should be a naked eye object. It will greatly help to position yourself to put the Sun just behind some obstruction. A building, a streetlight, anything to block the Sun’s glare and aid in picking out the comet. On the morning of the 15th the comet will rise 2° behind the Sun, thus 2° lower in the sky.

Give it a try!

A Daytime Comet!

C/2006 P1 McNaught is currently passing close to the Sun. At a mere 18 million miles (0.197 AU) from the Sun the intense solar radiation is causing the comet to boil and vent violently. The resulting cloud of gas and dust is reflecting enough sunlight to brighten the comet dramatically. Estimates are placing the comet at mag. -5 or even mag. -6. This is much brighter than even Venus! Some observers are reporting easy unaided eye visibility, but in the sky over Tucson a lot of dust and aerosols in the air are causing a great deal of glare around the Sun. Thus binoculars or a telescope is required to see the comet.

C/2006 P1McNaught
C/2006 P1 McNaught captured with a TV-76 operating at f/5 and a Canon 20Da DSLR, 1/8000 sec, gain at 100ISO. Taken 2:29pm 14 Jan, 2007 and processed with Photoshop. Three frames aligned and stacked in Photoshop to improve the signal to noise ratio.
The challenge is that Comet McNaught is just five degrees east of the Sun. Observing so close to the Sun presents distinct dangers, I do not want to fry my retina! So I carefully positioned my TV-76 on the alt-az mount so that the Sun was just behind the edge of my carport. Thus I could pan around and locate the comet with little fear of direct sunlight down the tube. A few frames with the Canon 20Da turned out OK but not great, those dust and aerosols in the sky and the resulting glare is reducing the signal to noise in the images. The photo to the right is a stack of three images in an attempt to improve the signal to noise, then greatly cropped in and levels adjusted in Photoshop.

The view was better in the eyepiece. A sharp point of the coma with a fan shaped tail. This really looks like a classic comet, I had not expected such a good tail in the bright sunlit sky. This is my first daytime comet, and since the opportunity may not come again anytime soon, this may be my only chance to see one, truly a once in a lifetime event!