What does OVV mean in UNCLASSIFIED
OVV stands for Optically Violent Variable. It is a rare type of cataclysmic variable star that exhibits extreme optical variability. OVV systems consist of a white dwarf accreting matter from a companion star, resulting in the emission of powerful jets of material and the production of bright optical outbursts.
OVV meaning in Unclassified in Miscellaneous
OVV mostly used in an acronym Unclassified in Category Miscellaneous that means Optically Violent Variable
Shorthand: OVV,
Full Form: Optically Violent Variable
For more information of "Optically Violent Variable", see the section below.
Characteristics of OVV
- Rapid and Large Optical Variability: OVV stars undergo sudden and dramatic changes in brightness, with variations of up to 10 magnitudes in a matter of hours or days.
- High Accretion Rates: The white dwarf in an OVV system accretes material from its companion at a high rate, leading to the formation of an accretion disk.
- Jet Production: OVV systems produce powerful jets of material that are ejected perpendicular to the accretion disk. These jets can extend millions of kilometers into space and emit strong radio and X-ray radiation.
- Outbursts: OVV stars experience periods of high activity called outbursts. During these outbursts, the accretion disk becomes unstable and undergoes a sudden increase in luminosity.
Physical Processes in OVV
The extreme variability and outbursts observed in OVV stars are driven by a combination of physical processes:
- Accretion Disk Instability: The accretion disk around the white dwarf becomes gravitationally unstable, leading to the formation of spiral arms and the development of a magnetic field.
- Jet Formation: The magnetic field generated in the accretion disk channels the accreting material into jets that are ejected perpendicular to the disk.
- Outburst Trigger: The buildup of material in the accretion disk can trigger an outburst when the pressure and temperature become too high.
OVV Classification
OVV stars are classified into two main subtypes:
- Type I OVV: These stars exhibit regular outbursts with periods ranging from a few hours to a few days.
- Type II OVV: These stars have less frequent and more irregular outbursts, with periods of months or years.
Essential Questions and Answers on Optically Violent Variable in "MISCELLANEOUS»UNFILED"
What are Optically Violent Variables (OVVs)?
OVV are a class of cataclysmic variable stars that display extreme and rapid variations in their optical brightness. They are characterized by sudden outbursts or dips in luminosity that occur over timescales ranging from minutes to days.
What causes the optical variability in OVV?
The optical variability in OVV is attributed to the interaction between a white dwarf and an accretion disk that surrounds it. The white dwarf, a compact and massive star remnant, accretes mass from the accretion disk. This process triggers the release of gravitational energy, which heats the disk and causes it to emit radiation. The observed optical variations result from changes in the accretion rate and the physical properties of the disk.
What are the different types of OVV?
OVV are classified into two main subtypes:
- Dwarf Novae: These OVV exhibit frequent and relatively small outbursts that typically last for several days to weeks. The outbursts are caused by sudden increases in the accretion rate onto the white dwarf.
How are OVV studied?
OVV are studied using a variety of astronomical techniques, including:
-
Photometry: Measuring the changes in optical brightness of OVV over time.
-
Spectroscopy: Analyzing the light from OVV to determine the physical properties of the white dwarf, accretion disk, and ejecta.
-
Time-resolved observations: Monitoring OVV over short timescales to capture the rapid changes in their brightness.
Final Words: Optically Violent Variables (OVV) are fascinating astrophysical objects that showcase extreme optical variability and outburst behavior. The physical processes underlying these phenomena involve complex interactions between accretion disks, magnetic fields, and jet formation. OVV stars provide valuable insights into the nature of cataclysmic variable stars and the role of accretion in shaping stellar evolution.
OVV also stands for: |
|
| All stands for OVV |