Solar Prominences

A solar prominence is a massive, bright feature extending outward from the Sun's surface into its outer atmosphere (the corona). 

They consist of relatively cool, dense plasma—primarily hydrogen and helium—held in place by tangled magnetic field lines.

When seen at the edge of the Sun against space, they appear as bright, glowing loops (often pinkish-red). When viewed against the bright solar disk, they look like dark, snake-like lines called filaments.

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.