🆕 CzSkY News

Two new annotated sketches were added to David Michalek’s double-star list: STF 299 and STF 113

🌕 Moon

• Full Moon: Friday 5 December at 00:14 CET
• Over the weekend it will pass near Jupiter.

🪐 Planets

• Mercury (≈ −0.5 mag): low in the morning sky; in very clear air it may be visible to the naked eye, but binoculars are recommended first.
• Venus (−3.9 mag): rises only after civil twilight → practically unobservable.
• Mars (1.4 mag): unobservable, still edging closer to the Sun in the sky.
• Jupiter (−2.5 mag): visible from late evening in the east below Castor and Pollux (Gemini), culminating high in the south in the second half of the night.
• Saturn (1.1 mag): in the evening after dusk above the southern horizon.
• Uranus (5.6 mag): fairly high in the evening sky in the east, about 4° below the Pleiades.
• Neptune (7.9 mag): near Saturn, about 4° to the left.

☀️ Sun Activity & a Chance of Auroras

Solar activity is very high again as active regions with large sunspots rotate into view. Over the weekend, a series of strong flares and plasma eruptions was observed near the Sun’s eastern limb. If this continues, conditions could again develop that allow auroras to be seen even from our latitudes.

The most prominent sunspot group is on the southern hemisphere in active region AR4294 (during the previous rotation it was quieter as AR4281), so there’s hope it’s now near its peak and may produce strong X-class flares.

Follow:

• English: Spaceweather.com, SolarHam
• Ongoing monitoring (also in Czech): SpaceWeatherLive
• Current imagery: SDO

🌠 Comets

Comet observing is currently limited by moonlight around the Full Moon. Morning conditions are better until 2 December (fully dark skies), and on 3 December the Moon sets only at astronomical twilight; after that, mornings also get worse.

• For now, evening comets effectively drop out: C/2025 R2 (SWAN) and C/2025 T1 (ATLAS) (moving near the “Coat Hanger” asterism below Cygnus).
• Before dawn, it’s worth trying C/2025 K1 (ATLAS) (brighter than expected as its nucleus is gradually fragmenting).
• You can also still follow the fairly bright interstellar comet 3I/ATLAS in Virgo.

Author: Martin Gembec