APOD: Great Conjunction: Saturn and... (2020 Dec 15)

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Expand view Topic review: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by JohnD » Wed Dec 23, 2020 10:42 am

Huh! Turbulence!? It's been persistently cloudy here ever since I heard of the GC. I saw tht Moon on Monday night, through cloud, that's it.
Cloudbait? Chris should move to here in the NorthWest UK!

Happy Christmas, All!
John

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by MarkBour » Tue Dec 22, 2020 10:05 pm

Chris Peterson wrote: Thu Dec 17, 2020 5:05 am
MarkBour wrote: Thu Dec 17, 2020 2:07 am
Chris Peterson wrote: Tue Dec 15, 2020 2:43 pm

I plan on shooting images around local noon on the 21st, which for me will put them in the southeastern sky just past their point of being closest (which is slightly before they rise for me).

Both of these objects are plenty bright to be telescopic objects in full daylight. I'll go for wider field astro-landscape type images just after sunset.
I hope you'll share some images with us. I hope you experience very good seeing at the Cloudbait observatory near Guffey, Colorado. Your elevation near 9000 feet should help!
I put up a couple of early images at viewtopic.php?f=8&t=19131&p=309046#p309046

Actually, the seeing here tends to be pretty bad, with the jet stream normally over us. Great transparency, but unsteady skies. Good for lots of deep sky imaging, not so good for high resolution planetary shots, though.
Thanks, enjoyed your posted images.

Sorry to hear about the jet stream's annoying effects. I haven't reached the point where I'd notice the effects of turbulence in the atmosphere usually, except when that turbulence is near the ground: Last night we set up in a field to view the conjunction through a scope and possibly even get some photos, but it was so windy (over 40 mph) that the scope wouldn't hold still and everything was shaking around. We would get some decent viewing, but no photos were worth a darn. So, that kind of air turbulence I can notice!

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by Chris Peterson » Thu Dec 17, 2020 5:05 am

MarkBour wrote: Thu Dec 17, 2020 2:07 am
Chris Peterson wrote: Tue Dec 15, 2020 2:43 pm
Case wrote: Tue Dec 15, 2020 10:51 am A tough one, so close to the setting Sun, so close to the horizon. On the other hand, this one is not about planetary surface details.
I plan on shooting images around local noon on the 21st, which for me will put them in the southeastern sky just past their point of being closest (which is slightly before they rise for me).

Both of these objects are plenty bright to be telescopic objects in full daylight. I'll go for wider field astro-landscape type images just after sunset.
I hope you'll share some images with us. I hope you experience very good seeing at the Cloudbait observatory near Guffey, Colorado. Your elevation near 9000 feet should help!
I put up a couple of early images at viewtopic.php?f=8&t=19131&p=309046#p309046

Actually, the seeing here tends to be pretty bad, with the jet stream normally over us. Great transparency, but unsteady skies. Good for lots of deep sky imaging, not so good for high resolution planetary shots, though.

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by neufer » Thu Dec 17, 2020 2:10 am

  • One of my highlights as a young boy during the 1954 Christmas season was my father driving me down to the (Swedish!?) Zeiss Planetarium at the University of North Carolina at Chapel Hill where they would stage their traditional sky show in which a live astronomer pondered the age-old question of the possible origin of the Star of Bethlehem.
https://www.space.com/14036-christmas-star-bethlehem-comet-planet-theories.html wrote:
Was the Star of Bethlehem a Star, Comet ... or Miracle?
By Joe Rao December 23, 2011

<<As a young boy, one of my highlights of the Christmas season was visiting New York's Hayden Planetarium where they would stage their traditional sky show in which astronomers pondered the age-old question of the possible origin of the Star of Bethlehem.

Between 1935 and 1959, Hayden's very first Zeiss projector (three others have been installed since) was run back some 2,000 years in an attempt to reproduce the positions of the planets around the time of the birth of Christ. The entire procedure would take four hours with the planets engaged in an incredible fast-moving dance while the moon flipped around the sky a hundred times a minute!

Ultimately, the projector was brought to a halt on Feb. 25 in the year 6 BC with the planets Jupiter, Saturn and Mars forming a triangle low in the western sky.

In those days, a silhouette of the skyline of New York was a permanent fixture around the periphery of the planetarium dome, so the planet trio was depicted not above a Middle East desert, but Midtown Manhattan. The audience was then asked: "Was the star seen by the Wise Men an unusual, eye-catching gathering of naked eye planets, or was that fabled 'sign in the sky' a meteor, comet, nova, or something supernatural?"

In later years, the tedious running-back of the projector was discontinued, mainly to save needless wear and tear on the machinery. In 1960, special auxiliary projectors were designed to depict the planet triangle. And the panorama silhouette of New York skyscrapers was replaced by a series of projectors which could replicate not just the skyline of New York, but scenes from any location on Earth. As such, Hayden audiences could now watch as Jupiter, Saturn and Mars drew near to each other over the landscape of Bethlehem.>>

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by MarkBour » Thu Dec 17, 2020 2:07 am

Chris Peterson wrote: Tue Dec 15, 2020 2:43 pm
Case wrote: Tue Dec 15, 2020 10:51 am A tough one, so close to the setting Sun, so close to the horizon. On the other hand, this one is not about planetary surface details.
I plan on shooting images around local noon on the 21st, which for me will put them in the southeastern sky just past their point of being closest (which is slightly before they rise for me).

Both of these objects are plenty bright to be telescopic objects in full daylight. I'll go for wider field astro-landscape type images just after sunset.
I hope you'll share some images with us. I hope you experience very good seeing at the Cloudbait observatory near Guffey, Colorado. Your elevation near 9000 feet should help!

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by alter-ego » Wed Dec 16, 2020 10:26 pm

Chris Peterson wrote: Wed Dec 16, 2020 3:43 pm
alter-ego wrote: Wed Dec 16, 2020 5:38 am
Chris Peterson wrote: Tue Dec 15, 2020 2:43 pm
I plan on shooting images around local noon on the 21st, which for me will put them in the southeastern sky just past their point of being closest (which is slightly before they rise for me).
Although not necessarily a plan changer, the closest separation occurs at positive altitudes for you. But there's an interesting twist for when the closest separation occurs. It involves topocentric circumstances.
That's interesting.

In reality, I'll probably be shooting images all day, and with different equipment. We'll see what I get.
I discovered a calculation error for the topocentric case so I corrected the post. However, the bottom line doesn't change; the conjunction should be visible to you at the time for the geocentric minimum.

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by neufer » Wed Dec 16, 2020 7:17 pm

Chris Peterson wrote: Wed Dec 16, 2020 3:24 pm
JohnD wrote: Wed Dec 16, 2020 3:20 pm
But the great Pre-Roman civilisation on the Tigris and Euphrates rivers, East of Jerusalem had priests magicians and astrologers, who WOULD have seen the Great Conjunction of their time in the West, as we do, and followed it towards Israel.

Massive movements like Christianity aquire much legend and folklore, but they do have sparks of truth in their origins.

For me, an atheist, I feel that there WAS someone called Jesus, born under a portenteous star, who grew up to be a philosopher and religious leader, who came to an awful end. His teaching on the way to conduct one's life is exemplary, such as respecting the family and giving charity by gifts (thoroughly good Jewish teaching too, of course!) so why not celebrate what we think was his birthday in that way?
  • "Portentous star" sounds a lot more astrological than astronomical.
https://en.wikipedia.org/wiki/Symphony_No._5_(Beethoven) wrote:
<<The Symphony No. 5 in C minor of Ludwig van Beethoven (baptised 17 December 1770), Op. 67, was written between 1804 and 1808. In an essay titled "Beethoven's Instrumental Music", published in three installments in December 1813, E.T.A. Hoffmann praised the "indescribably profound, magnificent symphony in C minor":
  • How this wonderful composition, in a climax that climbs on and on, leads the listener imperiously forward into the spirit world of the infinite!... No doubt the whole rushes like an ingenious rhapsody past many a man, but the soul of each thoughtful listener is assuredly stirred, deeply and intimately, by a feeling that is none other than that unutterable portentous longing, and until the final chord—indeed, even in the moments that follow it—he will be powerless to step out of that wondrous spirit realm where grief and joy embrace him in the form of sound....
https://en.wikipedia.org/wiki/Magi wrote:

<<Magi (from Latin magus) were priests in Zoroastrianism and the earlier religions of the western Iranians. The earliest known use of the word magi is in the trilingual inscription written by Darius the Great, known as the Behistun Inscription. Old Persian texts, predating the Hellenistic period, refer to a magus as a Zurvanic, and presumably Zoroastrian, priest.

Pervasive throughout the Eastern Mediterranean and Western Asia until late antiquity and beyond, mágos was influenced by (and eventually displaced) Greek goēs (γόης), the older word for a practitioner of magic, to include astronomy/astrology, alchemy and other forms of esoteric knowledge. This association was in turn the product of the Hellenistic fascination for (Pseudo‑)Zoroaster, who was perceived by the Greeks to be the Chaldean founder of the Magi and inventor of both astrology and magic, a meaning that still survives in the modern-day words "magic" and "magician".

In the Gospel of Matthew, "μάγοι" (MAGOI) from the east do homage to the newborn Jesus, and the transliterated plural "magi" entered English from Latin in this context around 1200 (this particular use is also commonly rendered in English as "kings" and more often in recent times as "wise men"). The singular "magus" appears considerably later, when it was borrowed from Old French in the late 14th century with the meaning magician.

The term only appears twice in Iranian texts from before the 5th century BCE, and only one of these can be dated with precision. This one instance occurs in the trilingual Behistun inscription of Darius the Great, and which can be dated to about 520 BCE. In this trilingual text, certain rebels have magian as an attribute; in the Old Persian portion as maγu- (generally assumed to be a loan word from Median). The meaning of the term in this context is uncertain.>>

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by Chris Peterson » Wed Dec 16, 2020 3:43 pm

alter-ego wrote: Wed Dec 16, 2020 5:38 am
Chris Peterson wrote: Tue Dec 15, 2020 2:43 pm
I plan on shooting images around local noon on the 21st, which for me will put them in the southeastern sky just past their point of being closest (which is slightly before they rise for me).
Although not necessarily a plan changer, the closest separation occurs at positive altitudes for you. But there's an interesting twist for when the closest separation occurs. It involves topocentric circumstances.
That's interesting.

In reality, I'll probably be shooting images all day, and with different equipment. We'll see what I get.

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by Chris Peterson » Wed Dec 16, 2020 3:24 pm

JohnD wrote: Wed Dec 16, 2020 3:20 pm The Magi went to Jerusalem and King Herod, "Saying, Where is he that is born King of the Jews? for we have seen his star in the east"
But the same verse in Matthew says "there came wise men from the east to Jerusalem". If from a point East of Jerusalem they had seen it in their East, they would have gone East and Jesus would have been born in India!
So the Bible is already confused!
But the great Pre-Roman civilisation on the Tigris and Euphrates rivers, East of Jerusalem had priests magicians and astrologers, who WOULD have seen the Great Conjunction of their time in the West, as we do, and followed it towards Isreal.

Massive movements like Christianity aquire much legend and folklore, but they do have sparks of truth in their origins.
For me, an atheist, I feel that there WAS someone called Jesus, born under a portenteous star, who grew up to be a philosopher and religious leader, who came to an awful end. His teaching on the way to conduct one's life is exemplary, such as respecting the family and giving charity by gifts (thoroughly good Jewish teaching too, of course!) so why not celebrate what we think was his birthday in that way?
John
"Portentous star" sounds a lot more astrological than astronomical.

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by JohnD » Wed Dec 16, 2020 3:20 pm

The Magi went to Jerusalem and King Herod, "Saying, Where is he that is born King of the Jews? for we have seen his star in the east"
But the same verse in Matthew says "there came wise men from the east to Jerusalem". If from a point East of Jerusalem they had seen it in their East, they would have gone East and Jesus would have been born in India!
So the Bible is already confused!
But the great Pre-Roman civilisation on the Tigris and Euphrates rivers, East of Jerusalem had priests magicians and astrologers, who WOULD have seen the Great Conjunction of their time in the West, as we do, and followed it towards Isreal.

Massive movements like Christianity aquire much legend and folklore, but they do have sparks of truth in their origins.
For me, an atheist, I feel that there WAS someone called Jesus, born under a portenteous star, who grew up to be a philosopher and religious leader, who came to an awful end. His teaching on the way to conduct one's life is exemplary, such as respecting the family and giving charity by gifts (thoroughly good Jewish teaching too, of course!) so why not celebrate what we think was his birthday in that way?
John

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by Chris Peterson » Wed Dec 16, 2020 2:26 pm

JohnD wrote: Wed Dec 16, 2020 10:36 am People ask, Is this the Christmas Star?
I read - I don't KNOW this sort of thing! - that planets' orbital mechnaics being completely calculable, there WAS such a Great Conjunction, in 7BC.
But there was another, between Jupiter and Venus, in 2BC. That would have been brighter than this one and must have drawn the attention of Magi, in large numbers! In terms of Biblical dating, an error of 2 years is surely insignificant, so this wasn't the Christmas Star, but it was one very like it!
The most compelling evidence is that the myth stems from astrological interpretations, not anything that was actually visible in the sky. (Remember that the Nativity stories weren't constructed until long after the events they purport to describe.)

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by neufer » Wed Dec 16, 2020 2:21 pm

JohnD wrote: Wed Dec 16, 2020 10:36 am
People ask, Is this the Christmas Star?

I read - I don't KNOW this sort of thing! - that planets' orbital mechnaics being completely calculable, there WAS such a Great Conjunction, in 7BC.
But there was another, between Jupiter and Venus, in 2BC. That would have been brighter than this one and must have drawn the attention of Magi, in large numbers! In terms of Biblical dating, an error of 2 years is surely insignificant, so this wasn't the Christmas Star, but it was one very like it!
https://en.wikipedia.org/wiki/Star_of_Bethlehem wrote:
Click to play embedded YouTube video.
<<In 1614, German astronomer Johannes Kepler determined that a series of three conjunctions of the planets Jupiter and Saturn occurred in the year 7 BC. He argued (incorrectly) that a planetary conjunction could create a nova, which he linked to the Star of Bethlehem. Modern calculations show that there was a gap of nearly a degree (approximately twice a diameter of the moon) between the planets, so these conjunctions were not visually impressive. An ancient almanac has been found in Babylon which covers the events of this period, but does not indicate that the conjunctions were of any special interest. In the 20th century, Professor Karlis Kaufmanis, an astronomer, argued that this was an astronomical event where Jupiter and Saturn were in a triple conjunction in the constellation Pisces. Archaeologist and Assyriologist Simo Parpola has also suggested this explanation.

In 6 BC, there were conjunctions/occultations (eclipses) of Jupiter by the Moon in Aries. "Jupiter was the regal 'star' that conferred kingships – a power that was amplified when Jupiter was in close conjunctions with the Moon. The second occultation on April 17 coincided precisely when Jupiter was 'in the east', a condition mentioned twice in the biblical account about the Star of Bethlehem."

In 3–2 BC, there was a series of seven conjunctions, including three between Jupiter and Regulus and a strikingly close conjunction between Jupiter and Venus near Regulus on June 17, 2 BC. "The fusion of two planets would have been a rare and awe-inspiring event", according to Roger Sinnott. Another Venus–Jupiter conjunction occurred earlier in August, 3 BC. These events however occurred after the generally accepted date of 4 BC for the death of Herod. Since the conjunction would have been seen in the west at sunset it could not have led the magi south from Jerusalem to Bethlehem.>>

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by JohnD » Wed Dec 16, 2020 10:36 am

People ask, Is this the Christmas Star?
I read - I don't KNOW this sort of thing! - that planets' orbital mechnaics being completely calculable, there WAS such a Great Conjunction, in 7BC.
But there was another, between Jupiter and Venus, in 2BC. That would have been brighter than this one and must have drawn the attention of Magi, in large numbers! In terms of Biblical dating, an error of 2 years is surely insignificant, so this wasn't the Christmas Star, but it was one very like it!

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by alter-ego » Wed Dec 16, 2020 5:38 am

Chris Peterson wrote: Tue Dec 15, 2020 2:43 pm
I plan on shooting images around local noon on the 21st, which for me will put them in the southeastern sky just past their point of being closest (which is slightly before they rise for me).
Although not necessarily a plan changer, the closest separation occurs at positive altitudes for you. I plotted JPL Horizons results.
  • The minimum separation actually occurs at ~18:30 12/21 UTC
    The plot compares the conjunction details, timing and separation, for the geocentric case plus topocentric circumstances: Colorado Springs, with and without refraction. As it should be, topocentric (without refraction) and geocentric cases agree very well. The addition of refraction (topocentric) introduces a relatively significant reduction in angular separation when the planets rise due to the refractive index gradient at low altitudes.
20yr Conjunction_Colorado Springs_ With & Without Ref.jpg
Of course, this is more an interesting detail than a practical one, but barring any observatory-view limitations and you should be able to observe the planets at minimum separation (~20°at CS, ~19° at Guffy). I don't find the refraction affect valuable here due to it's dynamic and unpredictable nature.

Edit: Discovered calculation error for topocentric circumstances. Corrected post accordingly.

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by Chris Peterson » Wed Dec 16, 2020 12:36 am

Quick and dirty- rapid setup of my little refractor. It was 12°F and I wasn't really dressed for it. Just after sunset on 15 Dec, bad seeing. But the first time I've ever had the pair in the same telescopic field.
_
E7_47402p1.jpg

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by orin stepanek » Tue Dec 15, 2020 11:50 pm

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by bystander » Tue Dec 15, 2020 10:38 pm

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by bls0326 » Tue Dec 15, 2020 8:21 pm

About an hour after sunset on Dec. 13th, I looked out my front door (facing south) and there they were! Quite obvious. Mostly clouds since then, but hoping for a view as they get closer together.

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by Chris Peterson » Tue Dec 15, 2020 6:36 pm

florid_snow wrote: Tue Dec 15, 2020 6:28 pm
Chris Peterson wrote: Tue Dec 15, 2020 2:43 pm
I plan on shooting images around local noon on the 21st, which for me will put them in the southeastern sky just past their point of being closest (which is slightly before they rise for me).

Both of these objects are plenty bright to be telescopic objects in full daylight. I'll go for wider field astro-landscape type images just after sunset.
Excellent point, my plan was to do basically the same but wait until they hit my local meridian. Are you thinking the trade-off of looking through more atmosphere, but at a less turbulent time might be worth it? Thanks for the tip!
The ecliptic is so low that the difference in altitude isn't very much from mid-morning to mid-afternoon. My main reasoning is that my observatory wall is already partly blocking the telescope, but I can see a bit lower towards the corners- SE and SW. I'll also try imaging later in the day, and the forecast is for clear skies, but you never know. so if I have a chance in the morning, I"m not going to overlook it!

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by florid_snow » Tue Dec 15, 2020 6:28 pm

Chris Peterson wrote: Tue Dec 15, 2020 2:43 pm
I plan on shooting images around local noon on the 21st, which for me will put them in the southeastern sky just past their point of being closest (which is slightly before they rise for me).

Both of these objects are plenty bright to be telescopic objects in full daylight. I'll go for wider field astro-landscape type images just after sunset.
Excellent point, my plan was to do basically the same but wait until they hit my local meridian. Are you thinking the trade-off of looking through more atmosphere, but at a less turbulent time might be worth it? Thanks for the tip!

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by Chris Peterson » Tue Dec 15, 2020 5:55 pm

E Fish wrote: Tue Dec 15, 2020 2:10 pm I wish some in the media (social and otherwise) wouldn't talk about this as if Saturn and Jupiter in conjunction is somehow going to be significantly brighter, though. I've seen some things implying it's going to be like a supernova. It's a really cool event but when it gets built up so much, the reality becomes a disappointment. That happens whenever Mars is at perigee. Invariably, there's something that goes around saying that Mars will be as big as the full Moon.

But the image is very nice to show what it will look like. Given my luck, it'll probably snowing in my area on that day. :)
Quite the opposite, in fact. This would be far more spectacular if the two planets were near opposition. In fact, they are nearing conjunction with the Sun, meaning they are close to being as small and dim as they ever get.

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by DL MARTIN » Tue Dec 15, 2020 5:29 pm

GREAT STUFF. Hope the media picks this illustration up globally. Thank you.

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by Chris Peterson » Tue Dec 15, 2020 2:43 pm

Case wrote: Tue Dec 15, 2020 10:51 am A tough one, so close to the setting Sun, so close to the horizon. On the other hand, this one is not about planetary surface details.
I plan on shooting images around local noon on the 21st, which for me will put them in the southeastern sky just past their point of being closest (which is slightly before they rise for me).

Both of these objects are plenty bright to be telescopic objects in full daylight. I'll go for wider field astro-landscape type images just after sunset.

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by E Fish » Tue Dec 15, 2020 2:10 pm

I wish some in the media (social and otherwise) wouldn't talk about this as if Saturn and Jupiter in conjunction is somehow going to be significantly brighter, though. I've seen some things implying it's going to be like a supernova. It's a really cool event but when it gets built up so much, the reality becomes a disappointment. That happens whenever Mars is at perigee. Invariably, there's something that goes around saying that Mars will be as big as the full Moon.

But the image is very nice to show what it will look like. Given my luck, it'll probably snowing in my area on that day. :)

Re: APOD: Great Conjunction: Saturn and... (2020 Dec 15)

by seadogzz » Tue Dec 15, 2020 12:54 pm

Thanks for your help

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