APOD: Star Trails of the North and South (2020 Feb 12)

Comments and questions about the APOD on the main view screen.
User avatar
APOD Robot
Otto Posterman
Posts: 3830
Joined: Fri Dec 04, 2009 3:27 am

APOD: Star Trails of the North and South (2020 Feb 12)

Post by APOD Robot » Wed Feb 12, 2020 5:05 am

Image Star Trails of the North and South

Explanation: What divides the north from the south? It all has to do with the spin of the Earth. On Earth's surface, the equator is the dividing line, but on Earth's sky, the dividing line is the Celestial Equator -- the equator's projection onto the sky.  You likely can't see the Earth's equator around you, but anyone with a clear night sky can find the Celestial Equator by watching stars move.  Just locate the dividing line between stars that arc north and stars that arc south. Were you on Earth's equator, the Celestial Equator would go straight up and down.  In general, the angle between the Celestial Equator and the vertical is your latitude.  The featured image combines 325 photos taken every 30 seconds over 162 minutes. Taken soon after sunset earlier this month, moonlight illuminates a snowy and desolate scene in northwest Iran. The bright streak behind the lone tree is the planet Venus setting.

<< Previous APOD This Day in APOD Next APOD >>

RocketRon

Re: APOD: Star Trails of the North and South (2020 Feb 12)

Post by RocketRon » Wed Feb 12, 2020 5:40 am

Marvellous effect.
Not sure I've seen that attempted before.

That tree looks like its having a bad hair day ?

User avatar
JohnD
Tea Time, Guv! Cheerio!
Posts: 1208
Joined: Wed Feb 16, 2005 2:11 pm
Location: Lancaster, England

Re: APOD: Star Trails of the North and South (2020 Feb 12)

Post by JohnD » Wed Feb 12, 2020 10:20 am

PLus 1 from me! When we see so many star trails, analemmas and other prolonged exposure pics on APOD, this is a first!
I know that like any publication, APOD can only put out what it receives, but please look out for more such original ideas.

John

Tszabeau

Re: APOD: Star Trails of the North and South (2020 Feb 12)

Post by Tszabeau » Wed Feb 12, 2020 1:53 pm

“ In general, the angle between the Celestial Equator and the vertical is your latitude.”

I’m guessing approx. 45 degrees north.

User avatar
orin stepanek
Plutopian
Posts: 5282
Joined: Wed Jul 27, 2005 3:41 pm
Location: Nebraska

Re: APOD: Star Trails of the North and South (2020 Feb 12)

Post by orin stepanek » Wed Feb 12, 2020 2:02 pm

The lone tree looks likr it's in an area under attack! :spam:

StarTrailsTree_Parchini_1080.jpg
You do not have the required permissions to view the files attached to this post.
Orin

Smile today; tomorrow's another day!

User avatar
neufer
Vacationer at Tralfamadore
Posts: 16805
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: APOD: Star Trails of the North and South (2020 Feb 12)

Post by neufer » Wed Feb 12, 2020 2:03 pm

Click to play embedded YouTube video.

Art Neuendorffer

User avatar
Chris Peterson
Abominable Snowman
Posts: 14816
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: APOD: Star Trails of the North and South (2020 Feb 12)

Post by Chris Peterson » Wed Feb 12, 2020 2:37 pm

JohnD wrote:
Wed Feb 12, 2020 10:20 am
PLus 1 from me! When we see so many star trails, analemmas and other prolonged exposure pics on APOD, this is a first!
I know that like any publication, APOD can only put out what it receives, but please look out for more such original ideas.
There have been a number of past APODs that featured star trail images centered on the equator, showing rotation about both the north and south poles.

https://apod.nasa.gov/apod/ap190321.html
https://apod.nasa.gov/apod/ap180208.html
https://apod.nasa.gov/apod/ap090314.html
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

TheZuke!
Ensign
Posts: 85
Joined: Fri Mar 22, 2019 2:19 pm

Re: APOD: Star Trails of the North and South (2020 Feb 12)

Post by TheZuke! » Wed Feb 12, 2020 3:04 pm

Taking in account the present precession of the Earth, is there a bright star that marks (scribes) the Celestial Equator?

User avatar
Chris Peterson
Abominable Snowman
Posts: 14816
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: APOD: Star Trails of the North and South (2020 Feb 12)

Post by Chris Peterson » Wed Feb 12, 2020 3:39 pm

TheZuke! wrote:
Wed Feb 12, 2020 3:04 pm
Taking in account the present precession of the Earth, is there a bright star that marks (scribes) the Celestial Equator?
Orion straddles the celestial equator, and Mintaka (the northernmost of the belt stars) sits just 19 arcmin south of the equator (compared with Polaris, which is over 30 arcmin from the celestial north pole).
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

TheZuke!
Ensign
Posts: 85
Joined: Fri Mar 22, 2019 2:19 pm

Re: APOD: Star Trails of the North and South (2020 Feb 12)

Post by TheZuke! » Wed Feb 12, 2020 4:08 pm

Chris Peterson wrote:
Wed Feb 12, 2020 3:39 pm
TheZuke! wrote:
Wed Feb 12, 2020 3:04 pm
Taking in account the present precession of the Earth, is there a bright star that marks (scribes) the Celestial Equator?
Orion straddles the celestial equator, and Mintaka (the northernmost of the belt stars) sits just 19 arcmin south of the equator (compared with Polaris, which is over 30 arcmin from the celestial north pole).
Thanks!

While out walking the dog last night (before moonrise), I had good views of the sky, from Ursa Major to Cass. to Sirius, and Lepus.
While Orion was about (guessing) 40 degrees above the horizon, I can't make out anything south of Lepus because of light pollution (sigh!)
It was the first time this year I saw Leo, and could just make out the brightest star of Cancer.

Every now and then the dog looks up at me and has a puzzled look, "what are you looking for? The rabbits and squirrels are down here!)

TheZuke!
Ensign
Posts: 85
Joined: Fri Mar 22, 2019 2:19 pm

Re: APOD: Star Trails of the North and South (2020 Feb 12)

Post by TheZuke! » Wed Feb 12, 2020 4:16 pm

RocketRon wrote:
Wed Feb 12, 2020 5:40 am
Marvellous effect.
Not sure I've seen that attempted before.

That tree looks like its having a bad hair day ?
I wish I had "a hair day"! :)

User avatar
MarkBour
Subtle Signal
Posts: 995
Joined: Mon Aug 26, 2013 2:44 pm
Location: Illinois, USA

Re: APOD: Star Trails of the North and South (2020 Feb 12)

Post by MarkBour » Wed Feb 12, 2020 9:49 pm

Chris Peterson wrote:
Wed Feb 12, 2020 3:39 pm
TheZuke! wrote:
Wed Feb 12, 2020 3:04 pm
Taking in account the present precession of the Earth, is there a bright star that marks (scribes) the Celestial Equator?
Orion straddles the celestial equator, and Mintaka (the northernmost of the belt stars) sits just 19 arcmin south of the equator (compared with Polaris, which is over 30 arcmin from the celestial north pole).
Good to know!

And today's image shows that Venus was sitting right on the celestial equator.
However, this was a coincidence. The Sun, Moon, and planets do not stay on the celestial equator.
Mark Goldfain