Comments and questions about the
APOD on the main view screen.
-
APOD Robot
- Otto Posterman
- Posts: 5493
- Joined: Fri Dec 04, 2009 3:27 am
-
Contact:
Post
by APOD Robot » Sat Jun 06, 2020 4:09 am
Comet PanSTARRs and the Galaxies
Explanation: Comet PanSTARRs, C/2017 T2, shared this stunning telescopic field of view with galaxies
M81 and M82 on May 22/23. Of course, the galaxies were some 12 million light-years distant and the comet about 14 light-minutes away, seen in planet Earth's sky toward the Big Dipper. A new visitor
from the Oort Cloud, this
Comet PanSTARRs was discovered in 2017 by the PanSTARRs survey telescope when the comet was over 1 light-hour from the Sun, almost as distant as the orbit of Saturn. With a beautiful
coma and dust tail, this comet has been a solid northern hemisphere performer for telescope wielding comet watchers this May, following its closest approach to the Sun on May 4.
In this deep image from dark California skies the outbound comet even seems to
develop a short anti-tail as it leaves the inner Solar System.
-
Boomer12k
- :---[===] *
- Posts: 2691
- Joined: Sun Apr 22, 2007 12:07 am
Post
by Boomer12k » Sat Jun 06, 2020 8:57 am
Nice shot of Panstarrs...great galaxies.
The weather finally got good and I was able to get out my Celestron Evolution 6.
Great to be viewing.
Wish I could see a comet.
:---[===] *
-
Ann
- 4725 Å
- Posts: 13668
- Joined: Sat May 29, 2010 5:33 am
Post
by Ann » Sat Jun 06, 2020 9:08 am
I like the APOD, and I was glad to see galaxy NGC 3077 included in
the M81-M82-NGC 3077 trio.
NGC 3077 is seen here in saturated colors in an image by Sydney.
Fascinatingly, Comet PanSTARRS seems to pay regular visits to the Earth, and grow an anti-tail around May 23 perhaps every seventh year. That is, it seems to grow a tail that seems to point in the wrong direction, opposite the direction of its other tail(s).
This is, however, an optical illusion.
Wikipedia wrote:
The antitail is formed of larger dust particles, which are less affected by the Sun's radiation pressure and tend to remain roughly in the comet's orbital plane and eventually form a disc along the comet's orbit due to the ejection speed of the particles from the comet's surface. As Earth passes through the comet's orbital plane, this disc is seen side on, and appears as the characteristic spike.
So does the antitail and its disc along the comet's orbit have anything to do with meteor showers like the
Leonids? Because this antitail leaves a "disc" of larger particles behind that the Earth might pass through at regular intervals, and as some of these larger particles slam into the Earth's atmosphere, they produce lots of meteors?
Ann
Color Commentator
-
orin stepanek
- Plutopian
- Posts: 8200
- Joined: Wed Jul 27, 2005 3:41 pm
- Location: Nebraska
Post
by orin stepanek » Sat Jun 06, 2020 10:32 am
PanSTARRs on the way back to Ortcloud! Thanks for the visit!
Orin
Smile today; tomorrow's another day!
-
Joe Stieber
- Science Officer
- Posts: 216
- Joined: Tue Aug 18, 2009 1:41 pm
- Location: Maple Shade, NJ
-
Contact:
Post
by Joe Stieber » Sat Jun 06, 2020 12:11 pm
Ann wrote: ↑Sat Jun 06, 2020 9:08 am
Fascinatingly, Comet PanSTARRS seems to pay regular visits to the Earth, and grow an anti-tail around May 23 perhaps every seventh year.
Which "Comet PanSTARRS"? The Pan-STARRS survey has discovered more than 200 comets so far. In any case, the subject of today's APOD, properly designated C/2017 T2 (PANSTARRS), has an eccentricity that's essentially 1, indicating a parabolic orbit. Therefore, if there would be any previous or future passes through the solar system, the time scale for them would be very, very long. That's basically what the initial "C" in the designation signifies, a comet that's a one-time visitor.
-
Sa Ji Tario
Post
by Sa Ji Tario » Sat Jun 06, 2020 3:39 pm
The explanation says that this hypothetical and probable spherical formation of several cometary bodies that originally had about 200 to 600 land masses, this surgical kite from the Oort cloud, was displaced to the center of the Solar System with annihilation and then they took different forms separating into spheres and torus, in theory, the Oort cloud is separated into an outer cloud of a spherical nature and the interior somewhat separated from it by tidal divisions having a disk and the agglomerations form a donut or torus.-
Who first idealized it was Öpik in the 30s of the last century and then in the 50s taken by Oort from whom he took his name.
Several theories are said about its formation, one of them is that within the Milky Way a cluster of 500 stars was formed with the Sun in the middle forming an extremely sparse globular cluster (seen from a certain distance) and that the interaction between the stars caused this cloud to form, which is still being modified, Oort's calculations make it feasible.-
The part of the mega molecular cloud that originated the Solar System was not homogeneous due to its large size and the bodies took the elements of the neighborhood when they coagulated and in the case of comets different signatures are observed but in the latter they seem to be original the same zone or fragmented from a larger one “to the best of my knowledge and belief”
-
Chris Peterson
- Abominable Snowman
- Posts: 18459
- Joined: Wed Jan 31, 2007 11:13 pm
- Location: Guffey, Colorado, USA
-
Contact:
Post
by Chris Peterson » Sat Jun 06, 2020 4:04 pm
Joe Stieber wrote: ↑Sat Jun 06, 2020 12:11 pm
Ann wrote: ↑Sat Jun 06, 2020 9:08 am
Fascinatingly, Comet PanSTARRS seems to pay regular visits to the Earth, and grow an anti-tail around May 23 perhaps every seventh year.
Which "Comet PanSTARRS"? The Pan-STARRS survey has discovered more than 200 comets so far. In any case, the subject of today's APOD, properly designated C/2017 T2 (PANSTARRS), has an eccentricity that's essentially 1, indicating a parabolic orbit. Therefore, if there would be any previous or future passes through the solar system, the time scale for them would be very, very long. That's basically what the initial "C" in the designation signifies, a comet that's a one-time visitor.
"C" comets are not usually one-time visitors, simply rare visitors, with orbital periods ranging from tens of thousands of years to millions of years. Only a few are perturbed into hyperbolic orbits by their inner system visit. Indeed, C/2017 T2 has been perturbed into a new orbit which much lower eccentricity than it had on its inbound journey, resulting in a new orbit with a mere 50 or 60 thousand year period (compared with 5-10 million years before it got kicked by Jupiter).
-
johnnydeep
- Commodore
- Posts: 3079
- Joined: Sun Feb 20, 2011 8:57 pm
Post
by johnnydeep » Sat Jun 06, 2020 4:55 pm
Chris Peterson wrote: ↑Sat Jun 06, 2020 4:04 pm
Joe Stieber wrote: ↑Sat Jun 06, 2020 12:11 pm
Ann wrote: ↑Sat Jun 06, 2020 9:08 am
Fascinatingly, Comet PanSTARRS seems to pay regular visits to the Earth, and grow an anti-tail around May 23 perhaps every seventh year.
Which "Comet PanSTARRS"? The Pan-STARRS survey has discovered more than 200 comets so far. In any case, the subject of today's APOD, properly designated C/2017 T2 (PANSTARRS), has an eccentricity that's essentially 1, indicating a parabolic orbit. Therefore, if there would be any previous or future passes through the solar system, the time scale for them would be very, very long. That's basically what the initial "C" in the designation signifies, a comet that's a one-time visitor.
"C" comets are not usually one-time visitors, simply rare visitors, with orbital periods ranging from tens of thousands of years to millions of years. Only a few are perturbed into hyperbolic orbits by their inner system visit. Indeed, C/2017 T2 has been perturbed into a new orbit which much lower eccentricity than it had on its inbound journey, resulting in a new orbit with a mere 50 or 60 thousand year period (compared with 5-10 million years before it got kicked by Jupiter).
So what then of Ann's statment that comet PanSTARRS pays regular visits to Earth and shows an anti-tail every seventh year? Is it really a different comet each time?
--
"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."{ʲₒʰₙNYᵈₑᵉₚ}
-
Chris Peterson
- Abominable Snowman
- Posts: 18459
- Joined: Wed Jan 31, 2007 11:13 pm
- Location: Guffey, Colorado, USA
-
Contact:
Post
by Chris Peterson » Sat Jun 06, 2020 5:06 pm
johnnydeep wrote: ↑Sat Jun 06, 2020 4:55 pm
Chris Peterson wrote: ↑Sat Jun 06, 2020 4:04 pm
Joe Stieber wrote: ↑Sat Jun 06, 2020 12:11 pm
Which "Comet PanSTARRS"? The Pan-STARRS survey has discovered more than 200 comets so far. In any case, the subject of today's APOD, properly designated C/2017 T2 (PANSTARRS), has an eccentricity that's essentially 1, indicating a parabolic orbit. Therefore, if there would be any previous or future passes through the solar system, the time scale for them would be very, very long. That's basically what the initial "C" in the designation signifies, a comet that's a one-time visitor.
"C" comets are not usually one-time visitors, simply rare visitors, with orbital periods ranging from tens of thousands of years to millions of years. Only a few are perturbed into hyperbolic orbits by their inner system visit. Indeed, C/2017 T2 has been perturbed into a new orbit which much lower eccentricity than it had on its inbound journey, resulting in a new orbit with a mere 50 or 60 thousand year period (compared with 5-10 million years before it got kicked by Jupiter).
So what then of Ann's statment that comet PanSTARRS pays regular visits to Earth and shows an anti-tail every seventh year? Is it really a different comet each time?
I don't know what comet she is talking about. PANSTARRS has discovered many periodic comets, including ones which have orbital periods on the order of seven years. Any short period comet that gets close enough to the Sun to become active will have debris in its orbit, and will commonly show an antitail when observed as we cross its orbital plane.
-
Ann
- 4725 Å
- Posts: 13668
- Joined: Sat May 29, 2010 5:33 am
Post
by Ann » Sat Jun 06, 2020 6:01 pm
Chris Peterson wrote: ↑Sat Jun 06, 2020 5:06 pm
johnnydeep wrote: ↑Sat Jun 06, 2020 4:55 pm
Chris Peterson wrote: ↑Sat Jun 06, 2020 4:04 pm
"C" comets are not usually one-time visitors, simply rare visitors, with orbital periods ranging from tens of thousands of years to millions of years. Only a few are perturbed into hyperbolic orbits by their inner system visit. Indeed, C/2017 T2 has been perturbed into a new orbit which much lower eccentricity than it had on its inbound journey, resulting in a new orbit with a mere 50 or 60 thousand year period (compared with 5-10 million years before it got kicked by Jupiter).
So what then of Ann's statment that comet PanSTARRS pays regular visits to Earth and shows an anti-tail every seventh year? Is it really a different comet each time?
I don't know what comet she is talking about. PANSTARRS has discovered many periodic comets, including ones which have orbital periods on the order of seven years. Any short period comet that gets close enough to the Sun to become active will have debris in its orbit, and will commonly show an antitail when observed as we cross its orbital plane.
Yes, I realize I was probably wrong here. I was talking about the comet that is featured in the link,
develop a short anti-tail, in the caption of today's APOD.
Ann
Color Commentator
-
ebrinks
- Asternaut
- Posts: 1
- Joined: Sat Jun 06, 2020 8:01 pm
Post
by ebrinks » Sat Jun 06, 2020 8:26 pm
To those of you familiar with the M81 triplet (M81-M82-NGC3077), in addition to the image being displayed with "North" roughly pointing to the right, the image is also a mirror image of what the system looks like 'on the sky'. Here is link to an image in the proper orientation,
https://www.astron.nl/dailyimage/main.php?date=20180823, with North up and east to the left obtained with the VLA by my colleague, Erwin de Blok. This shows not only the triplet in visible light, but in the left panel, in blue, the distribution of neutral atomic hydrogen gas, showing clearly the three members of the triplet are interacting.
-
sillyworm 2
Post
by sillyworm 2 » Sun Jun 07, 2020 12:44 am
This is off topic ..please excuse.I was watching cottonwood seeds floating through a rainstorm and it was a good example of the Universe and how when 2 galaxies emerge and there would be near zero collisions.This wasn't perfect as many seeds were destroyed..but I did see quite a scattering of ones that made it from 2 houses down.My apologies