Starship Asterisk*

Comet Jacques, Heart and Soul

Explanation: On July 13th, a good place to watch Comet Jacques was from Venus. Then, the recently discovered visitor (C/2014 E2) to the inner solar system passed within about 14.5 million kilometers of our sister planet. Still, the outbound comet will pass only 84 million kilometers from our fair planet on August 28 and is already a fine target for telescopes and binoculars. Two days ago, Jacques' greenish coma and straight and narrow ion tail were captured in this telescopic snapshot, a single 2 minute long exposure with a modified digital camera. The comet is flanked by IC 1805 and IC 1848, also known as Cassiopeia's Heart and Soul Nebulae. If you're stuck on planet Earth this weekend you can hunt for Comet Jacques in evening skies, or spot a Venus, Jupiter, crescent Moon triangle before the dawn.

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Nah, it was too cloudy on Venus on July 13. (And too cloudy and too southward for me here this weekend.)

What would cause it to be greenish?

metamorphmuses wrote:What would cause it to be greenish?

The colour is due to different gases in the comet.

The detail in the Heart and Soul Nebulae is amazing considering it is a 2 minute exposure!

starsurfer wrote:

metamorphmuses wrote:What would cause it to be greenish?

The colour is due to different gases in the comet.

Yes, that much I figured, but I was hoping someone might say which element or compounds specifically might be responsible....

metamorphmuses wrote:What would cause it to be greenish?

In an online description of 2009's Comet Lulin, I found this...

Lulin's green color comes from the gases that make up its Jupiter-sized atmosphere. Jets spewing from the comet's nucleus contain cyanogen (CN: a poisonous gas found in many comets) and diatomic carbon (C2). Both substances glow green when illuminated by sunlight in the near-vacuum of space.

Presumably, the same would hold true for this comet, especially the cyanogen, since it's described as being "found in many comets."

Rob

The greenish color is due to krypton, the same element that put superman out of his misery. Ionized krypton yields a greenish color. There may also be oxygen and nitrogen present as well organic gases such as methane. What causes the ionization of comet gas remains a mystery.

nurserydropout wrote:The greenish color is due to krypton, the same element that put superman out of his misery. Ionized krypton yields a greenish color. There may also be oxygen and nitrogen present as well organic gases such as methane. What causes the ionization of comet gas remains a mystery.

I believe you are confusing krypton with kryptonite. They're different, you know. Superman has no problem handling krypton.

Chris Peterson wrote:

nurserydropout wrote:The greenish color is due to krypton, the same element that put superman out of his misery. Ionized krypton yields a greenish color. There may also be oxygen and nitrogen present as well organic gases such as methane. What causes the ionization of comet gas remains a mystery.

I believe you are confusing krypton with kryptonite. They're different, you know. Superman has no problem handling krypton.

But didn't Krypton become kryptonite when it exploded?

Beyond wrote:

Chris Peterson wrote:

nurserydropout wrote:The greenish color is due to krypton, the same element that put superman out of his misery. Ionized krypton yields a greenish color. There may also be oxygen and nitrogen present as well organic gases such as methane. What causes the ionization of comet gas remains a mystery.

I believe you are confusing krypton with kryptonite. They're different, you know. Superman has no problem handling krypton.

But didn't Krypton become kryptonite when it exploded?

The rocks became kryptonite, the atmosphere remained krypton - wasn't that noble?

Awesome...

"Shot through the Heart...."

:---[===] *

My PAREIDOLIA is kicking in....THE SOUL NEBULA...looks like a KITTEN playing on its back....

or a puppy...or maybe a bear cub....

:---[===] *

Mr. Noodle wrote:The rocks became kryptonite, the atmosphere remained krypton - wasn't that noble?

Quite! Sometimes science can be a real gas.

meteor becomes meteorite
Krypton becomes Kryptonite very clever so if an apple falls to the ground it becomes applebite ?

starsurfer wrote:The detail in the Heart and Soul Nebulae is amazing considering it is a 2 minute exposure!

Not just the 2 minutes, as according to the Exif data that I found the image create date was "August 18, 2012 5:08:54PM (timezone not specified)" which is well before the reported date of the discovery of the comet on March 13 2014 . The explanation would seem to imply that the image was taken on July 13 2014 but I wonder if the date it was taken can be confirmed.

PS. Seeing the rapidly changing distances brought up through the "already a fine target" link were fascinating (well there are to me! ).

DavidLeodis wrote:Not just the 2 minutes, as according to the Exif data that I found the image create date was "August 18, 2012 5:08:54PM (timezone not specified)" which is well before the reported date of the discovery of the comet on March 13 2014 :!:. The explanation would seem to imply that the image was taken on July 13 2014 but I wonder if the date it was taken can be confirmed.

I'd put it about 20 August 2014 04:30 UT.

Chris Peterson wrote:

DavidLeodis wrote:Not just the 2 minutes, as according to the Exif data that I found the image create date was "August 18, 2012 5:08:54PM (timezone not specified)" which is well before the reported date of the discovery of the comet on March 13 2014 . The explanation would seem to imply that the image was taken on July 13 2014 but I wonder if the date it was taken can be confirmed.

I'd put it about 20 August 2014 04:30 UT.

That's close but 3:00 UT fits the star field better. Also, Dominique is from Gent, Belgium and assuming he was in the neighborhood to take the picture then sunrise occurred about 4:40 UT on the 20th. The sky was too light at 4:30.

Thanks Chris and alter-ego for your help.

I now realise that I may have inferred something that was not meant to be inferred. This part in the explanation "On July 13th, a good place to watch Comet Jacques was from Venus. Then, the recently discovered visitor (C/2014 E2) to the inner solar system passed within about 14.5 million kilometers of our sister planet" made me infer that the image was taken on July 13th, which also happened to be the date that Venus was closest to the comet. It seems to me that the mention of the comet's position in relation to Venus was unnecessary and that instead the date that the image was taken should have been stated.

DavidLeodis wrote:Thanks Chris and alter-ego for your help.

I now realise that I may have inferred something that was not meant to be inferred. This part in the explanation "On July 13th, a good place to watch Comet Jacques was from Venus. Then, the recently discovered visitor (C/2014 E2) to the inner solar system passed within about 14.5 million kilometers of our sister planet" made me infer that the image was taken on July 13th, which also happened to be the date that Venus was closest to the comet. It seems to me that the mention of the comet's position in relation to Venus was unnecessary and that instead the date that the image was taken should have been stated.

Yeah, sometimes one has to be careful when reading the descriptions. I've made similar misinterpretations.
I actually liked the Venus reference - I was curious what constellation it was in and how fast it was moving wrt the stars. Ok...that's a bit detailed, but the description did state the picture was taken two days earlier

Thanks alter-ego.

I feel very now as for some reason I will have read but not taken in the "Two days ago, Jacques' greenish coma and straight and narrow ion tail were captured in this telescopic snapshot" in the explanation. As the APOD is dated 2014 Aug 22 then that will mean the image was taken on August 20, as yourself and Chris have calculated. Apologies if I caused anyone any confusion with my original post. As a partial excuse I can say that the date taken that was given in the Exif data is clearly very wrong (note the year!).

DavidLeodis wrote:Thanks alter-ego.

I feel very now as for some reason I will have read but not taken in the "Two days ago, Jacques' greenish coma and straight and narrow ion tail were captured in this telescopic snapshot" in the explanation. As the APOD is dated 2014 Aug 22 then that will mean the image was taken on August 20, as yourself and Chris have calculated. Apologies if I caused anyone any confusion with my original post. As a partial excuse I can say that the date taken that was given in the Exif data is clearly very wrong (note the year!).

No worries, David.
Straight-up, honest discussion is nothing to feel embarrassed or down about! The cooperative addition of not seeing the "2 days" reference and the funky exif data conspired to your confusion. I'm willing to bet you're not the only one in this boat, and I'm willing to bet the posts resulting from your honest question(s) has helped others. Sharing your concern about something that didn't add up is a big part of what this forum is all about.
I applaud your willingness and desire to bring your questions forward without caveat or judgment.
Keep it up. You contributions help keep many of us thinking (like me)!

Thanks alter-ego for your nice comments.