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Planets over Perth (APOD 12 Sep 2008)
Posted: Fri Sep 12, 2008 12:58 pm
by bystander
http://apod.nasa.gov/apod/ap080912.html
Nice picture, but what is the star between Venus and Mars and to the right of Mercury?
Posted: Fri Sep 12, 2008 1:37 pm
by orin stepanek
The red ball over the skyscrapers; is that one of the planets? Looks awful big in comparison to the moon. I was thinking the three dots above it were the planets; or is one of them a star?
Orin
Posted: Fri Sep 12, 2008 1:43 pm
by bystander
orin stepanek wrote:The red ball over the skyscrapers; is that one of the planets? Looks awful big in comparison to the moon. I was thinking the three dots above it were the planets; or is one of them a star?
The three brightest white dots above the moon are the planets. I think the red light is one of those aircraft warning lights they put on top of towers and buildings. But there is a fourth, fainter white dot. What is it?
What is it?
Posted: Fri Sep 12, 2008 1:50 pm
by henk21cm
bystander wrote:But there is a fourth, fainter white dot. What is it?
Porrima, δVirginis
Posted: Fri Sep 12, 2008 2:04 pm
by orin stepanek
bystander wrote:orin stepanek wrote:The red ball over the skyscrapers; is that one of the planets? Looks awful big in comparison to the moon. I was thinking the three dots above it were the planets; or is one of them a star?
The three brightest white dots above the moon are the planets. I think the red light is one of those aircraft warning lights they put on top of towers and buildings. But there is a fourth, fainter white dot. What is it?
That's what I thought the red ball was until I read your first post. I blew the picture up and was able to see several stars; and what looked like a constellation over to the right of the planets. I couldn't quite make it out; but it looked like a triangle of stars.
Orin
Re: What is it?
Posted: Fri Sep 12, 2008 2:05 pm
by bystander
henk21cm wrote:Porrima, δVirginis
Thanks, Henk! But which is it? Porrima (gamma virginis / γ Vir) or Auva (delta virginis / δ Vir)
Either it's just a
barking dog or
the baby will be born head first.
Posted: Fri Sep 12, 2008 2:20 pm
by bystander
Just looked at the
uncropped photo. There are two more stars at the top, and one at the extreme top right, that form an arc with Mercury and Mars. Curious about them, too.
Posted: Fri Sep 12, 2008 2:27 pm
by bystander
orin stepanek wrote:That's what I thought the red ball was until I read your first post. I blew the picture up and was able to see several stars; and what looked like a constellation over to the right of the planets. I couldn't quite make it out; but it looked like a triangle of stars.
I'm talking about the faint white dot to the right of Mercury and almost in line with Venus and Mars. About where the fifth star (epsilon crucis / ε Cru) would be in the
Southern Cross.
Re: What is it?
Posted: Fri Sep 12, 2008 2:39 pm
by henk21cm
bystander wrote:henk21cm wrote:Porrima, δVirginis
Thanks, Henk! But which is it? Porrima (gamma virginis / γ Vir) or Auva (delta virginis / δ Vir) :?:
Excuse. γ Virginis
The other question: since it is still daylight here (monitor of 10 years old), i only see one, about the same height in the image as γ Virginis, at a distance from γ Virginis of the order of Moon-Mercury or Mars-Venus (in projection!). That could be δ Virginis.
Posted: Fri Sep 12, 2008 2:45 pm
by orin stepanek
I'm thinking that the triangle of stars that I spotted may be Bootes; but I don't know for sure.
Orin
Posted: Fri Sep 12, 2008 4:57 pm
by Chris Peterson
bystander wrote:Just looked at the
uncropped photo. There are two more stars at the top, and one at the extreme top right, that form an arc with Mercury and Mars. Curious about them, too.
Here is a chart showing the visible stars. Forming a triangle with Mercury and Venus is Zaniah, eta Virgo. All the visible stars in the central and right parts of the image are in Virgo. At the lower left you can see delta and gamma Crater, and possible a couple of other stars in Crater above them.
![Image](http://www.cloudbait.com/misc/20080912_apod_chart.jpg)
Posted: Fri Sep 12, 2008 5:31 pm
by bystander
Chris Peterson wrote:Here is a chart showing the visible stars. Forming a triangle with Mercury and Venus is Zaniah, eta Virgo. All the visible stars in the central and right parts of the image are in Virgo. At the lower left you can see delta and gamma Crater, and possible a couple of other stars in Crater above them.
Thanks, Chris! Zaniah (η Vir) was the one I was looking for. I guess that's Auva (δ Vir) between Porrima (γ Vir) and Vindemiatrix (ε Vir).
Posted: Fri Sep 12, 2008 5:59 pm
by Case
Chris Peterson wrote:[chart in photo]
Nicely done
![Very Happy :D](./images/smilies/icon_biggrin.gif)
Posted: Fri Sep 12, 2008 8:38 pm
by Earthbelow
I expected to see Venus in roughly the same line as the Moon, Mercury, and Mars. I thought Venus was roughly in their orbital plane.
Posted: Sat Sep 13, 2008 2:49 am
by twc
I thought because Mercury had an orbit so close to the sun that it almost never appeared in the night sky. In this photograph it appears so far above the horizon... I can visualize the angles that would create that scenario but I have never seen it that far away from the sun before.