Friday 3 April 2020

Earth Hour Part III - The measurements

Earth Hour intro + Part I can be found here

Earth Hour Part II - the Condo can be found here.

In this third part I will table the measurements made with Unihedron Sky Quality Meter


It is not a toy although so easy to use that even an astronomer can use it:

Circalunar variations of the night sky brightness -- an FFT perspective on the impact of light pollution

or

Circalunar variations of the night sky brightness/impact of light pollution

or

Night sky photometry and spectroscopy performed at the Vienna University Observatory Johannes Puschnig, Thomas Posch, Stefan Uttenthaler

- OK, so maybe more than 1 astronomer wants to play! Actually, this is an invention, I believe, by Canadian astronomer, Doug Welch, at McMaster University, Hamilton, Ontario.

The following was written last Saturday:
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Notes from Earth Hour, Sat Mar 28, 2020 between 20:30 and 21:30 Eastern Daylight Time.

I used a "Sky Quality Meter" to measure quantitatively the brightness of the sky
in 2 directions, sequentially, straight up or Zenith, and toward the North Celestial
Pole about which the sky appears to turn, approx 45° elevation for Orillia.

The sky was 8/8 cloudy between 20:00 and 22:00 but may have varied in altitude - I just
don't know. The readings are in magnitudes per square arc second, useful in astronomy.
Essentially bigger numbers are from darker sky.

Time     Zenith     North Celestial Pole

20:06     12.46        still in twilight
20:14                   14.22

20:32    16.69      16.71  Earth Hour start
21:00    16.71      16.96
21:15    17.66      17.07

21:35    16.92      17.09 end of Earth Hour

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Vicki and I intend to use this meter in our various outreach programs from  monitoring bats and Whip-poor-wills to the night sky brightness during observations of the stars.


WOB

2 comments:

  1. Bill, sadly I think people were distracted more than ever this year away from Earth Hour. Despite listening to the news more than ever, I heard no mention of this event. We observed it here by turning off all lights and power bars, and sitting by candle light. But looking out the windows at our neighbours' homes, most had exterior and interior lights on. At least water and air pollution has decreased during this pandemic with less traffic, fewer airplanes in flight and no new boat cruises.

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  2. Let's see what tonight brings. Rain is promised - check; and +3°C and miserable - check.

    I seem "good to go"?

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