What time will comet A3 be visible today and tomorrow? Comet A3, also known as Comet Tsuchinshan-ATLAS (C/2023 A3), is now putting on a show to those in the northern hemisphere.
It’s shining at a magnitude of about +4, first in the east before sunrise during late-Sept., then in the west after sunset in mid-Oct. Comet A3 has two tails, like most comets — a blue-ish plasma tail of ionized gas and a whitish dust tail of dust, rock and frozen gas.
With some good planning, clear weather and well-timed observing, comet A3 and its bright tail should make an eye-catching sight this late-Sept. and mid-Oct. Here’s how to see comet A3 this weekend.
Check my feed every day this week and next for a daily “comet tracker” with sky-charts and tips for viewing Comet A3.
Where To See Comet A3: Saturday, Sept. 28
Position: east-southeast, 22.5 degrees from the sun in Sextans
Time: an hour before sunrise where you are (around 07:00 in the U.S.)
Expected magnitude: +4.5
Comet’s distance from the sun: 58.6 million km
Comet’s distance from Earth: 131.5 million km
This morning, comet A3 will only be a day past perihelion, so it should be relatively bright, though low on the horizon. It should become visible —tail first — just above east-southeast about 75 minutes before sunrise and will be best seen in astronomical darkness, which lasts until about 60 minutes before sunrise. That’s a 15-minute window!
Where To See Comet A3: Sunday, Sept. 29
Position: east-southeast, 22.3 degrees from the sun in Leo
Time: an hour before sunrise where you are (around 07:00 in the U.S.)
Expected magnitude: +4.5
Comet’s distance from the sun: 58.9 million km
Comet’s distance from Earth: 124.9 million km
This morning, comet A3 will be visible a little closer to the east-southeast an hour before sunrise. It will be placed below a 9%-lit waning crescent moon and Regulus, the brightest star in the constellation Leo.
As yesterday, it should be visible just above east-southeast about 75 minutes before sunrise and will be best seen in astronomical darkness, which will last until about 60 minutes before sunrise. Another short window.
When To See Comet A3 In October 2024
Comet A3 will soon dip into the sun’s glare (from around Oct. 2), but will re-emerge in dusk around Oct. 12 for those in the northern hemisphere.
That’s set to be the most convenient time to see comet A3. Look to the west immediately after sunset to glimpse it possibly at its brightest and best, though in the evenings after Oct. 12, it will rise higher into the sky.
Wishing you clear skies and wide eyes.