by alter-ego » Sun Jun 18, 2023 3:38 am
Ann wrote: ↑Sat Jun 17, 2023 8:26 am
alter-ego wrote: ↑Sat Jun 17, 2023 5:26 am
Ann wrote: ↑Fri Jun 16, 2023 4:33 am
Beautiful picture! But I very much recommend
the vimeo!
That can't possibly be correct. In the vimeo, which was shot in Sweden, it seems to get dark around 8 p.m., and the Sun seems to rise around 6 a.m. It's not that dark anywhere in Sweden in June. I live in southernmost Sweden, where the summer nights are the darkest, and the Sun doesn't set here until just before 10 p.m., and it's broad daylight at 4 a.m.
I'd say that the vimeo was probably shot in April in Sweden.
Ann
Chris Peterson wrote: ↑Fri Jun 16, 2023 6:15 pm
...
The intensity of the light can be manipulated. The position of the Sun at sunrise, no. It is seen rising at 6am. That's consistent with April 5 (assuming a full Moon date) in southern Sweden.
These responses indicated to me there was some confusion somewhere. Ann thought that Summer daylight in Sweden was too long for the Vimeo exposures, Chris suggests a reasonable solution to this by proposing April as the month of the image, and lastly, the reference to "June full moon" removed from the main page. I love confusion (lol) so I joined this fray.
I've concluded that the APOD description is pretty messed up for whatever reason, and the image is really something way different.
I identified a narrow range of Vimeo frames that I think spells out the scoop here:
- Manually scanning through Vimeo, I reconstructed the FoV in Stellarium and ultimately simulated the Vimeo constellations passage over time:
→ The sky field (excluding foreground) is ~135° x 44°
→ Discovered the big dipper swings a wide range through lower culmination during darkness which is not possible until roughtly Aug - Dec
- Around 2:56 Vimeo time, I became aware of a bright object in Gemini (lower right):
→ I searched backward in 1-year increments until an object showed up.
→ Surprisingly, on Nov 25, 2010 (~19:20 for the frame I chose), an 81%-illuminated moon showed up in exactly the position of the unkown object! (Jupiter and Mars were never close)
Note: I found no date/time for when the image sequence was taken. Only that Vimeo was uploaded on June 8, 2023.
Bottom line:
- I'm confident the combined constellation IDs and the spot-on circumstances of the moon position clinches the Fall timing of the Vimeo frames.
- Total exposure time is not ~11½ hours (as in the description), but instead around 17 hours (a lengthy Fall night). For my chosen location of
Akersberga, Sweden, the sun sets on Nov 24 14:01UT and rises on Nov 25 7:09 UT or about 17 hours when the sun is below the horizon.
- Where exactly in the location in southern Sweden is not important. Location will affect sunrise/sunset times a little, but not so much the visible
nighttime constellations or the nugget moon location in Gemini.
I think this will hold true but I'm bothered by such disagreement in the APOD description.
Thanks, alter-ego! I love your detective work!
Ann
Thank you, Ann.
Two things have bothered me that I couldn't really accept. First was needing to go back to 2010 for a solution to the APOD timing. It just didn't feel right, and second, if that object was the moon, I thought I should be able to identify a bigger blob. I realized that I hadn't run across Venus in my searches and wondered if I missed it. Turns out I did (comes and goes pretty quickly!), and as close as I could tell, Venus does fit better amongst the stars by
maybe 0.5°. There are
only two dates between 2010 and now that are potential solutions: 9/1/2012, and
9/1/2020. I think the latter, most recent time is the most likely. For that night, the sun was below the horizon ~14 hours which is more in line with the APOD timescale, and a 98% full moon illuminated the scene the entire night.
I'm now satisfied with the solution
![Yes. :yes:](./images/smilies/yes.gif)
[quote=Ann post_id=331745 time=1686990382 user_id=129702]
[quote=alter-ego post_id=331743 time=1686979598 user_id=125299]
[b][/b][quote=Ann post_id=331728 time=1686890001 user_id=129702]
[img3="Sunset to Sunrise over the Baltic Sea.
Image Credit & Copyright: Bernd Pröschold (TWAN)"]https://apod.nasa.gov/apod/image/2306/baltic-sea-timelapse-image_with-timescale600.jpg[/img3]
Beautiful picture! But I very much recommend [url=https://vimeo.com/834367421]the vimeo[/url]!
That can't possibly be correct. In the vimeo, which was shot in Sweden, it seems to get dark around 8 p.m., and the Sun seems to rise around 6 a.m. It's not that dark anywhere in Sweden in June. I live in southernmost Sweden, where the summer nights are the darkest, and the Sun doesn't set here until just before 10 p.m., and it's broad daylight at 4 a.m.
I'd say that the vimeo was probably shot in April in Sweden.
Ann
[/quote]
[quote="Chris Peterson" post_id=331734 time=1686939340 user_id=117706]
...
The intensity of the light can be manipulated. The position of the Sun at sunrise, no. It is seen rising at 6am. That's consistent with April 5 (assuming a full Moon date) in southern Sweden.
[/quote]
These responses indicated to me there was some confusion somewhere. Ann thought that Summer daylight in Sweden was too long for the Vimeo exposures, Chris suggests a reasonable solution to this by proposing April as the month of the image, and lastly, the reference to "June full moon" removed from the main page. I love confusion (lol) so I joined this fray.
I've concluded that the APOD description is pretty messed up for whatever reason, and the image is really something way different.
I identified a narrow range of Vimeo frames that I think spells out the scoop here:
[list=1][*][i]Manually scanning through Vimeo, I reconstructed the FoV in Stellarium and ultimately simulated the Vimeo constellations passage over time:[/i]
→ The sky field (excluding foreground) is ~135° x 44°
→ Discovered the big dipper swings a wide range through lower culmination during darkness [b][size=110]which is not possible until roughtly Aug - Dec[/size][/b]
[*][i]Around 2:56 Vimeo time, I became aware of a bright object in Gemini (lower right):[/i]
→ I searched backward in 1-year increments until an object showed up.
→ Surprisingly, on Nov 25, 2010 (~19:20 for the frame I chose), an [b][size=120]81%-illuminated moon showed up in exactly the position of the unkown object![/size][/b] (Jupiter and Mars were never close)
Note: I found no date/time for when the image sequence was taken. Only that Vimeo was uploaded on June 8, 2023.[/list]
[b]Bottom line:[/b]
[list=•][*]I'm confident the combined constellation IDs and the spot-on circumstances of the moon position clinches the Fall timing of the Vimeo frames.
[*] Total exposure time [u]is not ~11½ hours[/u] (as in the description), but instead around 17 hours (a lengthy Fall night). For my chosen location of
Akersberga, Sweden, the sun sets on Nov 24 14:01UT and rises on Nov 25 7:09 UT or [u]about 17 hours when the sun is below the horizon[/u].
[*] Where exactly in the location in southern Sweden is not important. Location will affect sunrise/sunset times a little, but not so much the visible
nighttime constellations or the nugget moon location in Gemini.
[/list]
I think this will hold true but I'm bothered by such disagreement in the APOD description.
[/quote]
Thanks, alter-ego! I love your detective work!
Ann
[/quote]
Thank you, Ann.
Two things have bothered me that I couldn't really accept. First was needing to go back to 2010 for a solution to the APOD timing. It just didn't feel right, and second, if that object was the moon, I thought I should be able to identify a bigger blob. I realized that I hadn't run across Venus in my searches and wondered if I missed it. Turns out I did (comes and goes pretty quickly!), and as close as I could tell, Venus does fit better amongst the stars by [i]maybe[/i] 0.5°. There are [b]only two dates between 2010 and now that are potential solutions:[/b] 9/1/2012, and [color=#00BF00][b]9/1/2020[/b][/color]. I think the latter, most recent time is the most likely. For that night, the sun was below the horizon ~14 hours which is more in line with the APOD timescale, and a 98% full moon illuminated the scene the entire night.
I'm now satisfied with the solution :yes: