Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Magnetic Declination

Magnetic Declination

Magnetic declination is the angle between true north, which aligns with the Earth's rotational axis, and magnetic north, which follows the direction of the Earth's magnetic field. This discrepancy exists because the magnetic poles do not coincide with the geographic poles. The value of magnetic declination depends on the observer's location on Earth and is subject to changes over time due to the dynamic nature of the Earth's magnetic field.The declination is called eastern when magnetic north...

Apparent Weight and the Earth's Rotation

Apparent Weight and the Earth's Rotation

Since all objects on the Earth's surface move through a circle every 24 hours, there must be a net centripetal force on each object, directed towards the center of that circle. The points of the north and south poles are the only exception to this rule.
For an object on the Earth's equator, the net centripetal force that accounts for its rotation is the Earth's pull towards its center, or the weight minus the normal force that prevents it from piercing into the Earth's surface. This force,...

Relative Motion Analysis using Rotating Axes

Relative Motion Analysis using Rotating Axes

Consider a component AB undergoing a linear motion. Along with a linear motion, point B also rotates around point A. To comprehend this complex movement, position vectors for both points A and B are established using a stationary reference frame.
However, to express the relative position of point B relative to point A, an additional frame of reference, denoted as x'y', is necessary. This additional frame not only translates but also rotates relative to the fixed frame, making it instrumental in...

Relative Motion Analysis using Rotating Axes-Problem Solving

Relative Motion Analysis using Rotating Axes-Problem Solving

Consider a crane whose telescopic boom rotates with an angular velocity of 0.04 rad/s and angular acceleration of 0.02 rad/s2. Along with the rotation, the boom also extends linearly with a uniform speed of 5 m/s. The extension of the boom is measured at point D, which is measured with respect to the fixed point C on the other end of the boom. For the given instant, the distance between points C and D is 60 meters.
Here, in order to determine the magnitude of velocity and acceleration for point...

Rotation with Constant Angular Acceleration - II

Rotation with Constant Angular Acceleration - II

Kinematics is the description of motion. The kinematics of rotational motion discusses the relationships between rotation angle, angular velocity, angular acceleration, and time. One can describe many things with great precision using kinematics, but kinematics does not consider causes. For example, a large angular acceleration describes a very rapid change in angular velocity without any consideration of its cause. Thus, rotational kinematics does not represent the laws of nature.
The first...

Azimuths and Bearings

Azimuths and Bearings

Azimuths and bearings are essential concepts in surveying, providing methods to express the direction of a line relative to a meridian. Azimuths refer to the clockwise angle measured from the north end of a reference meridian to the given line, ranging from zero to 360 degrees. This method gives a comprehensive directional reference within a full 360-degree circle, making it a straightforward way to communicate direction in various fields, including navigation, cartography, and...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same journal

The Behaviour of the EUV Corona Before Flares in Regions with High Free Magnetic Energy.

Solar physics·2026

Same journal

Solar Cycle Variation of Sustained Gamma Ray Emission from the Sun.

Solar physics·2026

Same journal

The EUV Late-Phase: Statistical Results from 15 Years of Solar Dynamics Observatory Observations.

Solar physics·2026

Same journal

Investigating the Relationship Between Physical Properties and Spatial Irregularities at Coronal Hole Boundaries.

Solar physics·2026

Same journal

A Geomagnetic Estimate of Heliospheric Modulation Potential over the Last 175 Years.

Solar physics·2026

Same journal

Evolution of Open Magnetic Flux and Heliospheric Current Sheet-Associated Streamer Wind Across Multiple Solar Cycles.

Solar physics·2026

See all related articles

Search research articles

Related Experiment Video

Updated: Jun 16, 2026

Measuring Spatially- and Directionally-varying Light Scattering from Biological Material

Measuring Spatially- and Directionally-varying Light Scattering from Biological Material

Published on: May 20, 2013

SSTrack: An Automatic Sunspot Identification and Tracking Algorithm to Support the Measurement of Sunspot Rotation.

Charlotte Proverbs¹, Daniel Brown¹

¹Jeremiah Horrocks Institute, University of Lancashire, Preston, PR1 2HE UK.

|June 15, 2026

Summary

This summary is machine-generated.

A new automatic sunspot tracking method, SSTrack, aids in studying solar flares by analyzing sunspot rotation. This tool enables large-scale statistical surveys of solar activity for better understanding of eruptive events.

Keywords:

Rotation Solar Dynamics Observatory Sunspots

More Related Videos

Measurement of Aerosols Optical Thickness of the Atmosphere using the GLOBE Handheld Sun Photometer

Measurement of Aerosols Optical Thickness of the Atmosphere using the GLOBE Handheld Sun Photometer

Published on: May 29, 2019

Related Experiment Videos

Last Updated: Jun 16, 2026

Measuring Spatially- and Directionally-varying Light Scattering from Biological Material

Measuring Spatially- and Directionally-varying Light Scattering from Biological Material

Published on: May 20, 2013

Measurement of Aerosols Optical Thickness of the Atmosphere using the GLOBE Handheld Sun Photometer

Measurement of Aerosols Optical Thickness of the Atmosphere using the GLOBE Handheld Sun Photometer

Published on: May 29, 2019

Area of Science:

Solar Physics
Astrophysics
Space Weather

Background:

Sunspot motions deform the coronal magnetic field, storing energy released during solar flares.
Sunspot rotation contributes to energy buildup in active regions, potentially triggering eruptive solar events.

Purpose of the Study:

To develop a fully automatic method for identifying and tracking sunspots.
To enable large, unbiased statistical surveys of sunspot dynamics and their relationship to solar activity.

Main Methods:

Development of the automatic sunspot identification and tracking method, SSTrack.
Testing SSTrack on a four-month dataset previously analyzed with a semi-automatic tool.
Calculating sunspot rotation about umbral centers using tracking data.

Main Results:

SSTrack identified 54 of 56 sunspots from the previous sample and 43 additional ones.
SSTrack identified and tracked sunspots earlier and for longer durations than the semi-automatic method.
Both methods showed good agreement in rotation calculations for overlapping observations, though fragmentation affected the semi-automatic method.

Conclusions:

SSTrack is an efficient tool for large-scale statistical analysis of sunspot dynamics.
The method can capture fine-scale behaviors like sunspot splitting and mergers.
Accurate tracking is crucial for understanding the relationship between sunspot rotation and solar eruptive events.