Comet C/2025 R3 (PANSTARRS) taken from Sweden

Comet C/2025 R3 (PANSTARRS) is currently (April 2026) a bright object in the sky approaching its absolute maximum. It is currently visible to the naked eye under dark conditions and will reach its closest approach to the Sun (perihelion) on April 19, 2026.

The comet has reached a brightness (magnitude 3 to 4) that makes it visible without a telescope in places with little light pollution.

It is best seen in the morning sky just before dawn. It is currently located in the constellation Pegasus.

This is an extremely rare guest from the Oort cloud, having not visited the inner solar system in about 170,000 years.

Because it is a "hyperbolic" comet, scientists are unsure whether it will survive the intense heat of perihelion on April 19 or whether it will break apart.

The Sun

Solar filaments are enormous arcs of dense, ionized gas (plasma) that float above the surface of the Sun, held together by powerful and intricate magnetic fields. They are part of the Sun's dynamic atmosphere and are closely linked to the phenomenon of prominences.

1. What is the difference between a filament and a prominence?

They are essentially the same physical phenomenon, but the name comes from perspective:

Filament: When the structure is viewed from the front against the bright solar disk, it appears as dark, thread-like lines. This is because the plasma in the arc is slightly cooler (and therefore less luminous than the hot solar surface (photosphere) behind it).

Protuberance: When the structure is viewed at the edge of the Sun (limb) against the dark background of space, it appears as a bright, glowing arc extending from the solar surface.

2. Properties and Formation

Structure: Filaments form along magnetic "neutral lines" where regions of opposite magnetic polarity meet. They consist of fine threads that follow the magnetic field lines.

Size: They can be hundreds of thousands of kilometers long, which is often significantly larger than the Earth or even Jupiter.

Lifespan: Stable filaments can exist for anywhere from a few days to several months before either collapsing or breaking apart. Sun photographed 2026-04-11 Carpe Noctem Observatory.

 

Moon and Jupiter

A clear night in the Swedish mountains where the starry sky is free from light pollution. The bright planet Jupiter lies to the left of the moon this evening with the stars Castor and Pollux obliquely up to the left of Jupiter. Obliquely up to the right of the moon is the star Capella in the constellation Auriga. Below the moon and Jupiter is the constellation Orion with the bright star Sirius far down to the left. Around the moon are thin clouds that almost create a complete halo.