by johnnydeep » Sat Sep 12, 2020 3:47 pm
APOD Robot wrote: ↑Sat Sep 12, 2020 4:07 am
A Thousand Meteors
Explanation: Over a thousand meteors flash through the night in this
intriguing timelapse video. Starting in April 2019 the individual video frames were selected from 372 relatively clear nights of imaging from an automated wide-field observatory in rural New South Wales Australia. Arranged by
local sidereal time, a timekeeping system that uses the positions of stars to measure Earth's rotation, the frames follow the full annual progression of constellations through the wide field of view seen from 33 degrees south latitude. They capture a
diverse array of meteors including
sporadic meteors, bright fireballs, and shower meteors (plus a
lightning sprite), during the period. All frames were processed consistently and so show real variations in the local sky conditions.
Ok, so it took me a little while to appreciate that "Arranged by local sidereal time" means that the 372 separate night pictures, which were all taken at different times of the day, were reshuffled to appear in local sidereal time order so that we get the illusion of a single day progressing through a rotating starry sky, correct?
Also at 0:52 in the video, what are these two things - I want to say the little one is the SMC, but then the bigger one should be the LMC, but it looks too diffuse:
- What are these?
[quote="APOD Robot" post_id=306155 time=1599883627 user_id=128559]
[url=https://apod.nasa.gov/apod/ap200912.html] [img]https://apod.nasa.gov/apod/calendar/S_200912.jpg[/img] [size=150]A Thousand Meteors[/size][/url]
[b] Explanation: [/b] Over a thousand meteors flash through the night in this [url=https://vimeo.com/438799770]intriguing timelapse video[/url]. Starting in April 2019 the individual video frames were selected from 372 relatively clear nights of imaging from an automated wide-field observatory in rural New South Wales Australia. Arranged by [url=https://community.dur.ac.uk/john.lucey/users/lst.html]local sidereal time[/url], a timekeeping system that uses the positions of stars to measure Earth's rotation, the frames follow the full annual progression of constellations through the wide field of view seen from 33 degrees south latitude. They capture a [url=https://www.amsmeteors.org/meteor-showers/meteor-faq/]diverse array of meteors[/url] including [url=https://skyandtelescope.org/astronomy-blogs/explore-night-bob-king/random-meteors-arent-random02112015/]sporadic meteors[/url], bright fireballs, and shower meteors (plus a [url=https://earthobservatory.nasa.gov/images/86463/red-sprites-above-the-us-and-central-america]lightning sprite[/url]), during the period. All frames were processed consistently and so show real variations in the local sky conditions.
[/quote]
Ok, so it took me a little while to appreciate that "Arranged by local sidereal time" means that the 372 separate night pictures, which were all taken at different times of the day, were reshuffled to appear in local sidereal time order so that we get the illusion of a single day progressing through a rotating starry sky, correct?
Also at 0:52 in the video, what are these two things - I want to say the little one is the SMC, but then the bigger one should be the LMC, but it looks too diffuse:
[attachment=0]What Are These.JPG[/attachment]