Star flashing red in North sky

bilbot79

There's a star in the north sky at the moment and I always think it's flashing red. Is that just me? Anyone know what it is?

JustAThought

bilbot79 wrote: »

There's a star in the north sky at the moment and I always think it's flashing red. Is that just me? Anyone know what it is?

Is it venus that is red?

ps200306

bilbot79 wrote: »

There's a star in the north sky at the moment and I always think it's flashing red. Is that just me? Anyone know what it is?

I'd have a guess at Capella in Auriga. It's low on the horizon in the north these nights. It's conspicuous because there isn't much else in that direction in the sky, and it's the third brightest star visible from the northern hemisphere. It's flashing because it's only about ten degrees above the horizon, where air mass causes a lot of distortion. Different wavelengths are affected by different amounts, hence the flashing colours.


Capella is one of our just-about-circumpolar stars in Ireland. It gets down to below ten degrees altitude, but never goes below the horizon. At the other end of the year, in winter, it'll be above 80 degrees altitude and will be much less flashy because of the low air mass. At that time of year, Sirius will be doing what Capella is doing now. It's a southern hemisphere star (the brightest one in the sky) and doesn't get too far above our horizon, so it's common to see it flashing red and green.

Zubeneschamali

JustAThought wrote: »

Is it venus that is red?

Mars is the red planet, but this can't be any of the planets - planets are like the Sun and Moon, they cross the sky from East, across the Southern sky and set in the West.

This red star is in the North.

bilbot79

From the description I'd say capella. It was very low and directly north in early evening