A Thorne–Żytkow object (TZO) is a hypothetical type of astronomical object that is a unique combination of a neutron star and a red giant star. This concept arises from theoretical studies in astrophysics and is named after physicists Kip Thorne and Edward Żytkow, who proposed the idea in the 1970s.

The Hasegawa–Mima equation is a nonlinear partial differential equation that arises in the study of plasma physics, particularly in the context of magnetically confined plasmas, such as those found in fusion reactors. It describes the evolution of certain wave phenomena in a magnetized plasma, specifically the dynamics of plasma turbulence and the behavior of density perturbations.

The thin-film equation describes the evolution of a thin liquid film, typically on a solid substrate. This equation is important in fluid dynamics and materials science and is often used in contexts such as coatings, wetting, and thin-film flow dynamics. The thin-film equation can be derived from the Navier-Stokes equations under certain assumptions, specifically when considering a thin film with small thickness compared to its other dimensions.

Alpenglow refers to the phenomenon where mountains, typically at sunset or sunrise, are bathed in a warm, reddish or pinkish light. This effect occurs when the sun is just below the horizon, casting its rays onto the mountains. The light interacts with the atmosphere and the snow or rocky surfaces of the mountains, creating a beautiful visual display. Alpenglow is often most pronounced on the peaks and ridges, where the sunlight has a more direct angle.

Aurorasaurus is a citizen science project and online platform that allows individuals to report and track auroras, or the Northern and Southern Lights. Launched in 2014, Aurorasaurus aims to gather real-time data on auroral events by collecting reports from amateur astronomers, photographers, and the general public. Users can share their experiences and photographs of auroras, which are then mapped and made available to researchers and the public.

A keogram is a type of visual representation used primarily in the field of atmospheric science, particularly in the study of auroras and other phenomena related to the Earth's magnetosphere. It is a 2D image that captures the brightness or intensity of a specific phenomenon over time. In a keogram, time is represented on one axis (usually the horizontal axis), while the vertical axis represents a specific spatial dimension — often the zenith angle or latitude of the observation site.

A Lowitz arc refers to a specific type of arc in the context of singularities in mathematical functions or curves. More particularly, it is associated with certain kinds of algebraic varieties and homological properties in algebraic geometry. In the context of algebraic curves, a Lowitz arc is defined as a formal object that generalizes the notion of a point in algebraic geometry, allowing the study of families of points or infinite branches within a curve or surface.

The term "mirage" can refer to a few different concepts depending on the context: 1. **Optical Illusion**: In the most common sense, a mirage is an optical phenomenon that occurs when layers of air at different temperatures create a distortion in the way light travels. This often results in the appearance of water or a reflection of the sky on a hot road or desert surface. The light refracts due to temperature gradients and creates an image of something that isn't actually there.

The Parry arc, named after the geologist John Parry, refers to a specific feature in the context of glaciology and snow dynamics. It is a type of snow accumulation pattern that occurs on the leeward side (the side away from the wind) of an obstruction, such as a mountain or a ridge. When wind blows snow, it can create depositional areas where snow collects and builds up due to the reduction of wind speed and turbulence in the sheltered area.

A double sunset refers to a phenomenon where two sunsets can be observed in quick succession. This typically occurs in areas with unique geographical features, such as high mountains or deep valleys, where the sun can dip below the horizon at different heights or angles, allowing observers to see the sun set multiple times from varying perspectives. Double sunsets are sometimes seen in places like the Écrins National Park in France or in certain regions of the Arctic, where the landscape allows for this unusual optical effect.

Frazil ice is a type of ice that forms in water under specific conditions, typically in cold environments. It consists of small, loose crystals that form in supercooled water, usually in rivers and oceans, when the temperature of the water is below freezing but the water itself remains in a liquid state. Frazil ice typically forms when turbulent water is cooled rapidly, causing tiny ice crystals to develop and remain suspended in the water.

Polar night refers to a phenomenon that occurs in polar regions, where the sun does not rise above the horizon for an extended period, typically occurring during the winter months. This period of complete darkness can last for several weeks to several months, depending on the latitude. In places located above the Arctic Circle (66.5° N latitude) in the Northern Hemisphere or below the Antarctic Circle (66.

STEVE can refer to several different things depending on the context. Here are a few possibilities: 1. **STEVE (Super Tranquil Exosphere-Exoplanet Voyager Explorer)**: This is an acronym used in the context of space exploration or astronomy, though the exact meaning may vary based on specific discussions. 2. **STEVE (Satellite Tracking of Equatorial Vortices)**: This may refer to scientific projects or initiatives related to weather patterns and atmospheric studies.

Electric discharge refers to the flow of electric current through a medium, typically resulting from the breakdown of an insulating material or the movement of charge carriers in a conductive path. This phenomenon can occur in various forms and contexts, such as: 1. **Spark Discharge**: A quick, localized discharge of electricity that occurs when a high voltage exceeds the breakdown voltage of the surrounding medium (such as air), resulting in a visible spark.

The Ferranti effect is a phenomenon observed in electrical power systems, particularly in long transmission lines. It refers to the situation where the voltage at the receiving end of a long transmission line is higher than the voltage at the sending end. This can occur due to the capacitive nature of long transmission lines, especially when they are lightly loaded or operating at a high power factor.

The term "human-body model" can refer to various concepts depending on the context in which it's used. Here are a few interpretations: 1. **Anatomical Model**: In medical education, a human-body model typically refers to a physical or digital representation of the human body, used for the purpose of teaching anatomy, physiology, and medicine. These models can be detailed 3D representations that show bones, muscles, organs, and systems in the human body.

The photovoltaic effect is the creation of electric voltage or electric current in a material upon exposure to light. This phenomenon is the foundational principle behind photovoltaic cells, commonly known as solar cells, which are used to convert sunlight into electricity. Here's a more detailed explanation: 1. **Material Properties**: The photovoltaic effect occurs in certain materials, typically semiconductors, such as silicon. These materials have a band gap that allows them to absorb photons (light particles) with sufficient energy.

St. Elmo's fire is a phenomenon that occurs during thunderstorms, characterized by a visible blue or violet glow. It is caused by the ionization of air surrounding pointed or sharp objects, such as the mast of a ship or the spire of a church. When the electric field in the atmosphere becomes strong enough, it creates a discharge of electricity that results in a gentle and continuous glow at the tips of these objects. St.