Yukon Sky Report – October 2024
By: Shale Davis

The Moon

The Moon will begin the month close to the sun with New Moon falling on the second. This will be an annular solar eclipse though it will unfortunately only be visible in South America. Going forward it will reach Full Moon on the 17th This particular Full Moon will be a super moon which is about 14% brighter than a normal full Moon.

The Planets

This month three planets will be making appearances. Saturn will be visible shortly after sunset, hanging above the southern horizon. Jupiter and its cohort of moons will be rising slightly later in the evening from the east. Make sure to look out for the red bands that straddle the planet’s equator. And last but not least, Mars is continuing its return to our sky. It can be found at the feet of Gemini, not rising until early in the morning. With each passing day Mars is growing larger and brighter.

Comet C/2023 A3 (Tsuchinshan-ATLAS)

First Discovered by astronomers in early 2023 this comet has been racing towards the inner solar system for tens of thousands of years. On sept 27th it made its closest approach to the sun about the same distance as the Planet mercury. Astronomers were concerned that it may disintegrate due to its proximity the sun, but it appears to of survived more unless intact. C/2023 A3 now can be seen just above the setting sun. As the month progresses the apparent separation between the comet and the sun will grow making it more easily visible.

T Coronae Borealis Nova

Tucked away in the Corona Borealis constellation lies a seemingly inconspicuous star not even visible to the unaided eye. This is T Coronae Borealis, and it is in fact two stars (though they appear as only one) orbiting each other in violent dance. The larger component of the binary system is a massive red giant near the end of its life. The smaller member is an incredibly dense white dwarf (a stellar ember composed of electron degenerate matter). This White dwarf is gravitational stealing matter directly from the surface of its giant neighbour, creating an accretion (a ring of material orbiting its host). During outbursts the rate of transfer between the two stars increases dramatically, thus increasing the luminosity of the system. The last such outburst was in 1946 in which it temporarily brightened to magnitude +3, easily visible to the unaided eye. Another such outburst is anticipated sometime in the next few months.

Deep Sky Spotlight, Pleiades

One of the best examples of an open star cluster. the Pleiades rise above the horizon like a swarm of fireflies. they are a group a gravitationally associated middle aged stars which travel through space together. Spread among the stars are whispy clouds of interstellar gas and dust with an apparent blue hue. This gas is actually not glowing but rather reflecting light from the nearby stars.

The Pleiades. Image taken by S. Davis.