Jupiter appearing flashy - red on top, blue bottom

[bahamagreen]

Estimate about 30 degrees.
Antares is going to be just right and slightly lower than the moon this evening.

 

[sophiecentaur]

That's not an answer to the OP's question. The OP wasn't asking what object he was looking at, he was asking why it was flashing red and blue.

If it's a atmospheric effect then wouldn't everything else be doing it too?

If there's something special about planet viz, compared with stars then Saturn is not far away from Jupiter in the sky and you could expect the same weird effect. From a quick dabble with Stellarium, it seems likely that Big J is South and high in the sky (40deg up) at around midnight in Houston. In UK it's low at the mo and hard to see at its best. We have to wait for a couple of months, I think.
There is another possibility and that is the OP's actual vision (or dirty glasses??). J is pretty bright. But he says it's similar with binoculars. However, X8 is not a lot of magnification and J doesn't look very big - just brighter - until you use a bit of telescope magnification. It's very bright though and could be giving his eyes a harder time than anything else up there. (The Moon can be so bright that it's painful through a big scope and could give bad chromatic effects at its edge.) Planetary imaging tends to need a specialised scope with long objective + Barlow if you want to get a lot of pixels. A new club member was moaning, the other night, that he can't get convincing views of Jupiter and didn't seem to take my point about needing different gear for planets. (I blame all those stunning images that people post these days).

PS I suggested a possible vision problem because early cataracts seriously hamper my seeing many stars. It's only in dark conditions that it's a problem and your regular eye test doesn't explore that problem. The problem is that we (sufferers) often regard our vision as normal. (Same with hearing and my daughter made me get 'Deaf Aids' - magic! Bless her)

 

[DaveC426913]

If it's a atmospheric effect then wouldn't everything else be doing it too?

Yes. Everything does.

 

[sophiecentaur]

Yes. Everything does.

The original scenario was confusing. So it's just lousy weather for astronomy. What's new?

 

[DaveC426913]

A few years ago, I noticed this in my own swimming pool. I'd never seen such a thing and didn't know if it had a name but I figured out what it was.

Looking at things on the bottom of the pool at an oblique angle (the obliquer the better), everything had a halo of blue-green on its top edge and red on its bottom edge. Objects did not have any halo on their sides.

 

[bahamagreen]

Just to be clear, I thought it was Jupiter, but have since identified it is Antares.
Suggestions that the effect is Earth atmosphere, angle above horizon, or my eyes must explain why other objects (both planets and stars) at various angular elevations (including low ones) viewed both naked eye and with 10x binoculars do not exhibit the effect.

Per Wikipedia, Antares is surrounded by a large, red reflection nebula called the Rho Ophiuchi cloud complex (interstellar clouds with different nebulae), and they look interesting...

 

[sophiecentaur]

Lovely images but no one ever saw them. Those danged astrophotographers give beginners over optimistic ideas about what they will see with the telescope their auntie bought them for Christmas.

 

[DaveC426913]

Suggestions that the effect is Earth atmosphere, angle above horizon, or my eyes must explain why other objects (both planets and stars) at various angular elevations (including low ones) viewed both naked eye and with 10x binoculars do not exhibit the effect.

They do. It's just less noticeable.

 

[bahamagreen]

Also per Wikipedia, it's "one of the largest stars visible to the naked eye. Its exact size remains uncertain, but if placed at the center of the Solar System, it would reach to somewhere between the orbits of Mars and Jupiter."

Uncertainty of size is because it is increasingly diffuse with radius? Perhaps it is lensing something behind it?

I would still like to read descriptions from any here that have taken a look at it.

 

[DaveC426913]

Also per Wikipedia, it's "one of the largest stars visible to the naked eye.

Unusual. I looked for Antares, assuming it would be at the top of the size list, but did not find it near the top.

 

[Drakkith]

Uncertainty of size is because it is increasingly diffuse with radius? Perhaps it is lensing something behind it?

No, it's just due to the nature of the star. It doesn't even have a single size due to pulsations.
Per wiki:

Like most cool supergiants, Antares's size has much uncertainty due to the tenuous and translucent nature of the extended outer regions of the star. Defining an effective temperature is difficult due to spectral lines being generated at different depths in the atmosphere, and linear measurements produce different results depending on the wavelength observed.[49] In addition, Antares appears to pulsate, varying its radius by 19%

Unusual. I looked for Antares, assuming it would be at the top of the size list, but did not find it near the top.

Most very large stars are not visible to the naked eye. I assume that's why Antares was not near the top.

 

[DaveC426913]

Most very large stars are not visible to the naked eye. I assume that's why Antares was not near the top.

You'll have to get up earlier in the morning than that to fool me!

I did not look for largest stars; I looked for stars with largest apparent diameter.

https://en.wikipedia.org/wiki/List_of_stars_with_resolved_images
Antares is 18th from the top.

 

[Drakkith]

I did not look for largest stars; I looked for stars with largest apparent diameter.

Sort the list on your wikipedia link by angular diameter. Antares is 4th. Or 5th if you include the Sun.

 

[DaveC426913]

Sort the list on your wikipedia link by angular diameter. Antares is 4th. Or 5th if you include the Sun.

Fer cryin' out loud! I just assumed they were listed in descending order of size.

OK, as long as you're up by noon at the latest, you won't fool me.

 

[russ_watters]

The original scenario was confusing. So it's just lousy weather for astronomy. What's new?

What's new is the color separation effect that most people don't notice, but the OP did.

 

[bahamagreen]

What's new is the color separation effect that most people don't notice, but the OP did.

So far, I don't think anyone in this thread has observed Antares and described here what they did or didn't notice except me. I have been requesting people do just that and have been watching for such posts.

 

[russ_watters]

So far, I don't think anyone in this thread has observed Antares and described here what they did or didn't notice except me. I have been requesting people do just that and have been watching for such posts.

What exactly are you asking? That we look at Antares to confirm that it color-separates in bad seeing at low elevation, like you observed? I don't need to do that to confirm this is a thing.

 

[bahamagreen]

What exactly are you asking? That we look at Antares to confirm that it color-separates in bad seeing at low elevation, like you observed? I don't need to do that to confirm this is a thing.

I'd like people here with formal training and professional experience to look at the night sky and report if they see Antares flashing, if they see Antares doing this while the other stars and planets are not doing so, and if they see the colors - red dot on top, blue and green areas near the bottom.
I am not formally trained in optics, my descriptions are naive, and my suggestions of possible cause are relatively uninformed. I am hoping some trained experienced eyes may confirm and better describe the effect so someone might recognize the cause.
Specifically:
- why is Antares the only object I am noticing flashing?
- why is Antares the only object I am noticing flashing colors?

 

[russ_watters]

I'd like people here with formal training and professional experience to look at the night sky and report if they see Antares flashing...

This request is unnecessary and problematic. The effects are well known/understood, so you don't need a trained expert (I'm an amateur, but a pretty serious one), the effect is sky condition dependent and I'm still not convinced you know what object(s) you are looking at.

if they see Antares doing this while the other stars and planets are not doing so...

In addition to both effects being sky condition and object elevation dependent, the color separation/flashing also depends on our eye's poor ability to detect colors at night. So only bright objects near the horizon will show this combined effect to the naked eye.

Yes, I've seen this. I've photographed it. I've corrected it in the photos. These effects are not controversial/are well known to astronomers. Processing software even has built-in features to deal with it:
http://www.astronomie.be/registax/registax5usermanual.pdf
Page 48:

RGB Align toolWINDOW
Sometimes images have shifted colour-layers after stacking, this can be the case due to using different
files for each colour-layer and less then perfect alignment/optimisation or due to atmospheric effects.
The RGB Align tool is a very simple tool to improve the image quality.

Another source:

In addition to turbulence, the atmosphere creates another imaging problem referred to as differential atmospheric refraction. In effect, the atmosphere acts as a giant, but very-weak prism. Blue light is bent downward more strongly than red light. This results in a smearing of planetary imagery into a vertical spectrum. The amount of this smearing depends on the planet’s elevation angle.

https://astronomytechnologytoday.com/2017/07/06/atmospheric-dispersion-corrector/

It also describes that optical correction lenses can be made for this problem.

 

[JennaStarry-Eyed]

I just looked now, naked eye and binoculars.
With naked eye there is a red dot at the top of the disc that appears and disappears every few seconds with a general flashiness near the bottom of the disc.
With binoculars, the general flashiness looks more green than blue, the red dot is easy to see.
May I ask that people take a look, naked eye and with equipment, to at least confirm and maybe better describe what is seen?

I saw this tonight just with the naked eye. A red flash next to Jupiter. I was mesmerised. Birmingham, UK