Starship Asterisk*

dineshns wrote: ↑Wed Apr 06, 2022 2:50 am I captured a very colorful star assuming it is Sirius, But not sure.

Click to play embedded YouTube video.

Ann wrote: ↑Wed Apr 06, 2022 6:27 am

dineshns wrote: ↑Wed Apr 06, 2022 2:50 am I captured a very colorful star assuming it is Sirius, But not sure.

Click to play embedded YouTube video.

I don't think it is Sirius, because the star you filmed is quite red. Of course, if Sirius is low in the sky, it will be reddened.

I think that the star you filmed could possibly be Arcturus.

Click to play embedded YouTube video.

Sirius twinkling.

Click to play embedded YouTube video.

Arcturus twinkling.

I have once seen Arcturus twinkle in a manner similar to the star you have filmed. Arcturus seemed to sparkle and emit strong twinkles of red and green.

Ann

Chris Peterson wrote: ↑Wed Apr 06, 2022 2:37 pm
I'd go with Sirius. That's exactly what it looks like in a long exposure much of the time, being very bright and often low in the sky for northern observers. You can't really say anything about the color of the star here.

Ann wrote: ↑Wed Apr 06, 2022 4:11 pm

Chris Peterson wrote: ↑Wed Apr 06, 2022 2:37 pm
I'd go with Sirius. That's exactly what it looks like in a long exposure much of the time, being very bright and often low in the sky for northern observers. You can't really say anything about the color of the star here.

Sirius is certainly the "twinkliest" star in the sky. It sparkles in all colors of the rainbow, but it is indeed dominated by bluish and greenish hues.

Sirius is always relatively low in the sky from the latitudes of Sweden, but I have never seen Sirius look obviously yellow in the sky. Still, I realize that atmospheric conditions can affect Sirius to make it look yellow. I have also never seen a color picture where Sirius looks yellow, but I realize that a photo of a yellow-looking Sirius can be processed into an image where Sirius looks white or blue.

We should probably ask the photographer. Was the star that he filmed high or low in the sky? Had the sunset some hours before been unusually red, so that the atmosphere might have been unusually dusty?

The varying twinkly hues of Rigel, Betelgeuse and Sirius. Image via Amanda Cross.

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Take a look at the picture above. It is interesting that Rigel and Betelgeuse are not all that "twinkly", whereas Sirius, by contrast, twinkles almost madly. It changes color as it does so, too, and as the series of images show, Sirius does indeed "flash red", too. But it is not, unless circumstances are very unusual, persistently dominated by red and yellowish hues.

I think that the video that dineshns posted shows us a star that is yellower in color than we expect Sirius to be. It is certainly still possible that the star is in fact Sirius, but it looks much more like a low and twinkly Arcturus to me.

Ann

dineshns wrote: ↑Wed Apr 06, 2022 2:50 am I captured a very colorful star assuming it is Sirius, But not sure.

Click to play embedded YouTube video.

Katharine Schwab of Fast Company wrote about Steve Brown:

The amateur U.K.-based astrophotographer Steve Brown managed to capture that stunning spectrum of light in his photo Scintillating Sirius, which was recently shortlisted for the Insight Astronomy Photographer of the Year awards. The image is a composite created by shooting video of the star deliberately out of focus, so the light of the star shows up on film like a lens glare. Brown then chose the most vibrant, unexpected colors and put them together into a composite image. The final shot has 782 twinkles of different colored light.

Ann wrote: ↑Wed Apr 06, 2022 7:22 pm

Katharine Schwab of Fast Company wrote about Steve Brown:

The amateur U.K.-based astrophotographer Steve Brown managed to capture that stunning spectrum of light in his photo Scintillating Sirius, which was recently shortlisted for the Insight Astronomy Photographer of the Year awards. The image is a composite created by shooting video of the star deliberately out of focus, so the light of the star shows up on film like a lens glare. Brown then chose the most vibrant, unexpected colors and put them together into a composite image. The final shot has 782 twinkles of different colored light.

As you can see, Steve Brown's composite portrait of Sirius is much bluer in color than the star in your film

dineshns wrote: ↑Wed Apr 06, 2022 9:00 pm Thank you for all your replies. I am very new to the astro universe. Some answers to questions came up below.

Location : NZ (Auckland)
Time 9:30pm (Sunset around 6:00pm)
Visible in the sky from: East (a little bit to the north) is about a 30-40 degree angle above the horizon.
Environment; Clear sky no dust at all.
Based on Star Walk App: Sirius can visible from west (If I got it right

I captured this on Sunday 3rd April. After that didn't have a clear sky. Today looks good and I will try to get more info.

Thank you Again
Dinesh

Ann wrote: ↑Thu Apr 07, 2022 4:40 am Dineshns, I think Arcturus is just right. It makes perfect sense that your star is Arcturus if it was low in the sky when you filmed your star.

I have seen Arcturus sparkle madly just once, but I will never forget it. It positively seemed to fire red and green flashes. Arcturus was indeed low in the sky when I saw it sparkle like that.

I think Arcturus is a likelier candidate for your star than Spica, for two reasons. First, Spica is intrinsically blue-white, whereas Arcturus is intrinsically yellow-orange. Second, Arcturus is considerably brighter in our skies than Spica. The apparent (visual) magnitude of Arcturus is −0.04, which makes it one of the brightest-looking stars in the Earth's skies. Spica, by contrast, has an apparent magnitude of +0.97, which is considerably fainter. See the List of brightest stars.

Because Arcturus is brighter in our skies than Spica, we can expect it to twinkle more.

However, if the star you filmed was 30 to 40 degrees high up in the sky, it couldn't have been Arcturus, according to what Chris said about the position of Arcturus at the time and place when you filmed your star. But I keep insisting that the star you filmed looks like Arcturus.

Ann