APOD: Comet C/2017 K2 (PanSTARRS) (2022 Jun 30)

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APOD Robot
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APOD: Comet C/2017 K2 (PanSTARRS) (2022 Jun 30)

Post by APOD Robot » Thu Jun 30, 2022 4:05 am

Image Comet C/2017 K2 (PanSTARRS)

Explanation: Imaged on June 20 2022, comet C/2017 K2 (PanSTARRS) shares this wide telescopic field of view with open star cluster IC 4665 and bright star Beta Ophiuchi, near a starry edge of the Milky Way. On its maiden voyage to the inner Solar System from the dim and distant Oort cloud, this comet PanSTARRS was initially spotted over five years ago, in May 2017. Then it was the most distant active inbound comet ever found, discovered when it was some 2.4 billion kilometers from the Sun. That put it between the orbital distances of Uranus and Saturn. Hubble Space Telescope observations indicated the comet had a large nucleus less than 18 kilometers in diameter. Now visible in small telescopes C/2017 K2 will make its closest approach to planet Earth on July 14 and closest approach to the Sun this December. Its extended coma and developing tail are seen here at a distance of some 290 million kilometers, a mere 16 light-minutes away.

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RocketRon

Re: APOD: Comet C/2017 K2 (PanSTARRS) (2022 Jun 30)

Post by RocketRon » Thu Jun 30, 2022 4:50 am

Interesting.
How do we know its on its "maiden voyage to the inner Solar System" ?

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Ann
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Re: APOD: Comet C/2017 K2 (PanSTARRS) (2022 Jun 30)

Post by Ann » Thu Jun 30, 2022 5:50 am

RocketRon wrote: Thu Jun 30, 2022 4:50 am Interesting.
How do we know its on its "maiden voyage to the inner Solar System" ?
Good question, and you'll have to ask someone else, for example Chris.

For myself, I'll marvel at the three-dimensional nature of the Universe. (Yes, yes, I know it's four-dimensional. Bear with me.)

APOD 30 June 2022 annotated Comet and IC 4665.png

Bright Beta Ophiuchi is just some 80 light-years away, very comparable to the distance of the "five inner stars" of the Big Dipper. Beta Oph is a modest star as red giants go, radiating some 40 solar luminosities at visible wavelengths. It is comparable to Pollux.

IC 4665 is a nice cluster, some 1,000 light-years away. All its dominant members are B-type stars, so it is quite comparable to the Pleiades.

HS 161820 is a background star, some 2,000 light-years away. Its color, brightness and spectral class makes it quite comparable to Aldebaran.

Ann
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VictorBorun
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Re: APOD: Comet C/2017 K2 (PanSTARRS) (2022 Jun 30)

Post by VictorBorun » Thu Jun 30, 2022 7:54 am

RocketRon wrote: Thu Jun 30, 2022 4:50 am Interesting.
How do we know its on its "maiden voyage to the inner Solar System" ?
Its inbound orbit was hyperbolic (=unclosed) and its velocity suggested something like descending from slow motion position at 0.8 ly from Sun, in the Oort cloud.
It must have took millions of years to fall from that place.

The constellation of Draco is 83° from Ecliptic, or near Sun's north pole; but we believe the Oort cloud to be a bubble rather than a disk, so that is alright.

This visit will take this comet to an elliptic orbit, with a period of 18 000 years

All I said comes from here: https://en.wikipedia.org/wiki/C/2017_K2_(PanSTARRS)

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orin stepanek
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Re: APOD: Comet C/2017 K2 (PanSTARRS) (2022 Jun 30)

Post by orin stepanek » Thu Jun 30, 2022 1:43 pm

2017K2_2022-06-20_media1024.jpg
A new visitor from the Ort cloud! I hope it becomes naked eye
visible! 8-) I'll mark July down for sky watching! :yes:
STScI-01EVVB4GFKHZ98NK10CS6DY8SK.png
2017 K2's orbital path!
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Chris Peterson
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Re: APOD: Comet C/2017 K2 (PanSTARRS) (2022 Jun 30)

Post by Chris Peterson » Thu Jun 30, 2022 2:23 pm

RocketRon wrote: Thu Jun 30, 2022 4:50 am Interesting.
How do we know its on its "maiden voyage to the inner Solar System" ?
We don't "know" it. But its orbital parameters and origin in the Oort cloud make that the most likely (by far) possibility.
Chris

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Sa Ji Tario

Re: APOD: Comet C/2017 K2 (PanSTARRS) (2022 Jun 30)

Post by Sa Ji Tario » Thu Jun 30, 2022 2:32 pm

In the image that Ann inserted and next to Oph's coma, there is a very distant frontal spiral galaxy, I found about 20 in the image but very small