What did you see in the sky tonight?

[Ann]

There are noctilucent clouds outside my window again tonight. This time of year is noctilucent clouds season at my latitude, but you can never predict when these delicate silver-blue veins of the sky will show up. It always makes me happy to see them.

But I'm not going out for them tonight. I'll stay inside and watch them from my kitchen.

Ann

[Jerome68]

I am sorry but I had to share it, but this summer in Germany the only thing we are seeing is clouds... .

First said that I am 100% against climate change, but last year at least it was some nice sky nights without clouds and illuminated by the moon. But this one, already in July.... it seems almost like a lottery if we get a night like this than other things. However, for the rest of you, if you are leaving in a sunny place (yes, sunny for me it means basically no clouds), enjoy the nights during this summer!

[Chris Peterson]

Still following NEOWISE, at the thoroughly unpleasant hour of 4am. Looking forward to it being an evening object in a week or so. This is processed from a stack of nine images exposed from 0.25 to 60 seconds to bring out the detail. Whatever is going on in that coma is very interesting. (The second shot is pushed in the blue channel to emphasize the ion tail.)
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[Orca]

I caught a glimpse of NEOWISE! It was still visible just above the horizon around 10:00. The comet just happened to end up in a gap between trees. The tall trees around my area can make it difficult to see objects that are near the horizon.

[BDanielMayfield]

Caught my first ever view of a comet at about 10:15 local time, (Mountain Daylight Saving Time), 7/14/20. NEOWISE was just barely visible to the naked eye, but was impressive in my 7x50 binoculars.

Also got a look at Jupiter and three of its moons in my spotting scope while waiting for the sky to darken enough to find the comet.

[rstevenson]

I was ready to go out for a look at the comet this evening but the sky is too hazy at the moment. That’s generally true here, being on a sea coast and our location on the downwind side of the city, so no surprise there. But I happened to notice in another app that the ISS would be passing almost directly overhead — just a degree off the zenith, and just an hour or so after sunset. I had high hopes it would be bright enough to cut through the haze and it did. So I had 5 minutes of mild excitement and mosquito swatting, then back inside. What a life of excitement I lead!

Rob

[BDanielMayfield]

I made another attempt to see NEOWISE last night, but an hour or so later than the successful try my previous post reported. I drove out of town to a nearby dark sky site but found the northwestern sky littered with unforecasted broken cloud cover and found nada. I drove home, parked in our brightly light polluted apartment parking lot and took a look back toward the northwest. Hay, what's that light streak above the trees, could it be? I walked beyond the parking lot, got in the shadow of a large pine, pointed my binoculars and bam, their it was, looking much finer in the darker sky than it had three nights before.

Moral of the story is keep trying. ''Tis well worth the effort.

Bruce

[Cousin Ricky]

I saw comet C/2020 F3 NEOWISE tonight. I needed binoculars to find it, but once I did, I just needed averted vision to keep up with it naked eye. I wasn’t able to make out the split tail.

Six other people showed up on the same quest, so I got in an impromptu sidewalk astronomy session, my first since the pandemic arrived. It was different, staying 2 meters apart, speaking through masks, unable to share binoculars, and my laser pointer decided to die, forcing me to resort to things like “lower left of that cloud,” and “7 o’clock below the Big Dipper’s bowl,” but we managed.

[gntekas]

Dotion Tower

https://www.facebook.com/11341602705292 ... 150768676/

George Ntekas

Chios Island,Greece

[Chris Peterson]

Now that NEOWISE is moving away from the Sun, the cyanogen glow of the coma is no longer overwhelmed by scattered sunlight. Quite beautiful. Stacked from 15 each 1-minute RGB exposures (45 minutes total) taken with my RC10.
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[neufer]

Now that NEOWISE is moving away from the Sun,
the cyanogen glow of the coma is no longer overwhelmed by scattered sunlight.

• However, the violet CH cyanogen glow IS overwhelmed by the green C₂ glow:

<<When distant from the sun a comet looks like an asteroid, however, as it approaches the sun its surface begins to warm which in turns starts to sublimate its constituent ices which include Water, Carbon Dioxide and others. In the vacuum of space most ices sublimate, that is pass from the solid to gas phase without becoming a liquid. Because of outgassing dust and ice grains are also released, and these all combine to form a large cloud around the nucleus which typically extends 100,000 km or more, which is about the size of Jupiter. During the Rosetta mission it was found that Water and Carbon Dioxide liberated from the nucleus of Comet 67P were dissociated from free electrons, creating other products (like Diatomic Carbon and Hydrogen, among others).

C2 has 2 bright emission lines in the green. (COMET LOVEJOY : 2013)

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Often coma shine a vivid green, something some people can see even by direct observation by eye. Spectroscopic observations of coma reveal the main cause of this to be fluorescing diatomic carbon (C₂) and Cyanogen (CN) which are presumably the byproduct of the dissociation of ices containing Carbon (CO₂) and Nitrogen (Ammonia) from the nucleus surface. This can be seen in the adjacent (COMET LOVEJOY : 2013) spectra obtained by renown French amateur astronomer Christian Buil.

Surround the nucleus and coma, but not visible in the visual spectrum is a large cloud of Hydrogen atoms, which extends well beyond the normal coma and most likely is derived from the dissociation of water from the nucleus. It can only be detected from outside the earth's atmosphere because of the wavelengths it emits. In the case of Comet Hale-Bopp in 1997 the Hydrogen envelope extended 1 Astronomical Unit!>>

[Ann]

Spectra of Comet Lovejoy (2013). Credit: Christian Buil.

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Thanks for posting that comet spectrum, Art. It demonstrates perfectly why comet comas are not only green, but a bluish shade of green.

Comet Lovejoy (2013) was seen to have two bright emission lines in the green part of the spectrum at around 520 nm, but it also had a "cluster" of emission lines at around 470 nm. And as you said, Art, this comet also had a bright spike deep in the violet (ultraviolet?) part of the spectrum at about 390 nm.

Compare the difference between shades of "comet green" and "aurora green" (and yes, I realize that there are yellower comet comas and bluer auroras, but these are typical hues to me):

Coma of Comet C/2015 ER61 (PANSTARRS) from April 7, 2017. Credit: Terry Lovejoy.

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Aurora borealis from Kiruna, Sweden. Source: https://cityphototour.com/sv/tours/hunt-northern-lights-kiruna-abisko/

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[zeecatman]

Tonight I walked outside and was greeted almost immediately by one of the brightest shooting stars I'd ever seen! Judging by the direction, I figured it most likely came from the aquarids, but with my limited knowledge of meteor showers I don't want to count out the perseids as a possible source. I sat for a while and waited for more, but I only saw the one. I imagine under darker conditions the sky would be alive with trails.

Since this is my first post, I wanted to mention that a few nights ago I also got my first telescope-assisted view of the enormous smear in the sky that is the Andromeda galaxy. Despite how difficult it was to make out and how nearly formless it is in my bright sky, it took my breath away the moment I found it. Needless to say, visually observing an entity about 10^20 times your size (if I have the math right) is pretty staggering...

[Chris Peterson]

Last night (2020-08-11 UT 03:30) C/2020 F3 (NEOWISE) and C/2017 T2 (PANSTARRS), a couple of the more interesting comets of the last months, passed about 2.7° of each other. Here they are in a single frame that is 3.7° x 1.2°. Two shots mosaiced, with a Canon 7D, 2-min exposure, ISO 1600 on a Stellarvue 102A refractor. NEOWISE on the right, PANSTARRS (much dimmer) in the lower left.
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[Ann]

Last night (2020-08-11 UT 03:30) C/2020 F3 (NEOWISE) and C/2017 T2 (PANSTARRS), a couple of the more interesting comets of the last months, passed about 2.7° of each other. Here they are in a single frame that is 3.7° x 1.2°. Two shots mosaiced, with a Canon 7D, 2-min exposure, ISO 1600 on a Stellarvue 102A refractor. NEOWISE on the right, PANSTARRS (much dimmer) in the lower left.
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neo+pan.jpg

Very interesting, Chris. I like the bright green coma of comet NEOWISE. This green hue is noticeably absent in the portrait in today's APOD of the changing tails of comet NEOWISE.

Ann

[XgeoX]

Had a great run tonight! With my little 100mm scope I was able to pick out the GRS on Jupiter with some excellent views of the cloud bands. Went over to Saturn with stunning steady views of the rings though I wasn’t able to make out the Cassini division. Was able to clearly make out cloud smudge which was nice.
Saving the best for last I got some stunning views of Mars! The south polar cap was absolutely radiant! Putting on a moon filter I was able to make out a nice bit of detail in the southern highlands.
Overall a great night!

Eric

[BDanielMayfield]

Arcturus. Hardly report worthy, right? It's the brightest star in the northern night sky after all. But tonight it was the only visible star, period. But it was much dimmer than normal and reddish, like Mars. Bright Jupiter was visible but nearby Saturn was just barely so.

The cause was forest fires to our southwest, mainly in northern California. Last night I could see the faint band of the Milky Way running through Cassiopeia. 24 hrs later, only one single, stinking star.

Smoke stinks.

[Chris Peterson]

The Moon. Barely... through the smoke from countless fires. Could just see Jupiter through it. And the nearest big fire is over 100 miles away.
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[Chris Peterson]

The Moon and Mars, close together but moving apart. The first image was taken shortly after moonrise, 2020-09-06 UT 04:22. The second was taken around sunrise, 2020-09-06 UT 12:11 (so about eight hours later). Both images are at the same scale (but are likely rescaled on the webpage). You'll probably need to scroll the later image to see both objects.
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[Ann]

The Moon and Mars, close together but moving apart. The first image was taken shortly after moonrise, 2020-09-06 UT 04:22. The second was taken around sunrise, 2020-09-06 UT 12:11 (so about eight hours later). Both images are at the same scale (but are likely rescaled on the webpage). You'll probably need to scroll the later image to see both objects.
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E7_47077p.jpg
E7_47099p.jpg

Great pictures, Chris. Superb color contrasts particularly in the first image. Here the Moon has a brownish tint too, which I appreciate, since the Moon does indeed have a dark reddish tint.

Ann

[Chris Peterson]

The Moon and Mars, close together but moving apart. The first image was taken shortly after moonrise, 2020-09-06 UT 04:22. The second was taken around sunrise, 2020-09-06 UT 12:11 (so about eight hours later). Both images are at the same scale (but are likely rescaled on the webpage). You'll probably need to scroll the later image to see both objects.
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E7_47077p.jpg
E7_47099p.jpg

Great pictures, Chris. Superb color contrasts particularly in the first image. Here the Moon has a brownish tint too, which I appreciate, since the Moon does indeed have a dark reddish tint.

Ann

I should note that the Moon was low in the sky on the first shot, and very high on the second. Since we have somewhat smoky skies now, that makes the low altitude Moon particularly red in comparison with the high altitude one. The post processing of the two images is identical. In the later shot, you can see that the Moon has waned just a bit, and that it is less reddened by the atmosphere.

[Chris Peterson]

Finally had a couple of clear nights, without snow, without clouds, without smoke, without a Moon. So I thought I'd point the scope at something and make sure things were still working. Picked NGC 6951 for no particular reason, except it was high in the sky and looked kind of cool in pictures- a slightly asymmetric barred spiral galaxy. And surprise! Turned out to be a very interesting choice, as it lies behind a nice band of dust in our own galaxy, sometimes called "galactic cirrus" or "integrated flux nebula". Local dust illuminated only by the glow of the Milky Way. I'm amazed how bright it is, showing up in just a few minutes of exposure. Anyway, I collected eight hours of light and ended up with this. Seeing the wisps of foreground clouds gives the scene a very 3D look to my eyes.
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[Ann]

Finally had a couple of clear nights, without snow, without clouds, without smoke, without a Moon. So I thought I'd point the scope at something and make sure things were still working. Picked NGC 6951 for no particular reason, except it was high in the sky and looked kind of cool in pictures- a slightly asymmetric barred spiral galaxy. And surprise! Turned out to be a very interesting choice, as it lies behind a nice band of dust in our own galaxy, sometimes called "galactic cirrus" or "integrated flux nebula". Local dust illuminated only by the glow of the Milky Way. I'm amazed how bright it is, showing up in just a few minutes of exposure. Anyway, I collected eight hours of light and ended up with this. Seeing the wisps of foreground clouds gives the scene a very 3D look to my eyes.
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NGC6951_8h.jpg

That's a great image, Chris. The galaxy looks very fine, and the IFN looks fantastic.

I checked out some other pictures of NGC 6951. Many of them show galactic cirrus, and most of them show the cirrus to be reddish. This image is an interesting example.

I also checked out NGC 6951 with my software, and I was astonished at this galaxy's red color. Its B-V index is 0.99, which is very red indeed for a spiral galaxy and even redder than our big bully of a neighbor, Andromeda, which is itself really quite red as spiral galaxies go with a B-V index of 0.92.

This makes me ask two questions, maybe even three. Could the light of NGC 6951 be reddened by the IFN that might be located right in front of it from our point of view? Did you, Chris, use red-sensitive equipment for your image?

And why is the IFN so red? How red is our galaxy?

Ann

[Chris Peterson]

Finally had a couple of clear nights, without snow, without clouds, without smoke, without a Moon. So I thought I'd point the scope at something and make sure things were still working. Picked NGC 6951 for no particular reason, except it was high in the sky and looked kind of cool in pictures- a slightly asymmetric barred spiral galaxy. And surprise! Turned out to be a very interesting choice, as it lies behind a nice band of dust in our own galaxy, sometimes called "galactic cirrus" or "integrated flux nebula". Local dust illuminated only by the glow of the Milky Way. I'm amazed how bright it is, showing up in just a few minutes of exposure. Anyway, I collected eight hours of light and ended up with this. Seeing the wisps of foreground clouds gives the scene a very 3D look to my eyes.
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NGC6951_8h.jpg

That's a great image, Chris. The galaxy looks very fine, and the IFN looks fantastic.

I checked out some other pictures of NGC 6951. Many of them show galactic cirrus, and most of them show the cirrus to be reddish. This image is an interesting example.

I also checked out NGC 6951 with my software, and I was astonished at this galaxy's red color. Its B-V index is 0.99, which is very red indeed for a spiral galaxy and even redder than our big bully of a neighbor, Andromeda, which is itself really quite red as spiral galaxies go with a B-V index of 0.92.

This makes me ask two questions, maybe even three. Could the light of NGC 6951 be reddened by the IFN that might be located right in front of it from our point of view? Did you, Chris, use red-sensitive equipment for your image?

And why is the IFN so red? How red is our galaxy?

Ann

I started out with this little project mainly just to get my observatory tuned up. I wasn't expecting the IFN, so that caught me by surprise. Most galaxies (to me) aren't overly interesting in color, so I just shot luminance data. But this is a pretty active galaxy, which could be fun to get some color info on, as well as color for the IFN. So I may go back and try that.

I don't think the IFN is actually all that red. It's dust which is illuminated by relatively white light. We see that in a lot of nebula images, and it always looks similar: brown. Because the "real" colors of most astronomical objects are fairly subdued, it is very common for imagers to boost saturation in order to emphasize color. Boosting brown makes it into orange or red. I think that's all that's going on in most of the color images. The IFN is best described as brown, visually.

[BDanielMayfield]

Finally had a couple of clear nights, without snow, without clouds, without smoke, without a Moon. So I thought I'd point the scope at something and make sure things were still working. Picked NGC 6951 for no particular reason, except it was high in the sky and looked kind of cool in pictures- a slightly asymmetric barred spiral galaxy. And surprise! Turned out to be a very interesting choice, as it lies behind a nice band of dust in our own galaxy, sometimes called "galactic cirrus" or "integrated flux nebula". Local dust illuminated only by the glow of the Milky Way. I'm amazed how bright it is, showing up in just a few minutes of exposure. Anyway, I collected eight hours of light and ended up with this. Seeing the wisps of foreground clouds gives the scene a very 3D look to my eyes.
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NGC6951_8h.jpg

Glad someone's skies have cleared, and to see the nice galaxy image you captured Chris.

Here in our part of Idaho the smoke has gotten bad again. Two nights ago I could just barely make out Saturn, with averted vision, and only because of knowing its location relative to bright Jupiter. There were only two stars visible in the whole sky, Vega and Altair high overhead. But last night nothing; not even Jupiter was visible.