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Sunspots (Solar Dynamics Observatory)

The ring of fire from March 2010

 Automatic translation  Automatic translation Updated June 01, 2013

Launched February 11, 2010, SDO is the most sophisticated spacecraft ever designed to study the sun. After a series of small adjustments engine, SDO has stabilized its geosynchronous orbit. During his five-year mission, this space telescope will examine the Sun's magnetic field allows a better understanding of the role the sun plays on the Earth's atmospheric chemistry and climate. Since its launch, the engineers have done for 2 months, testing and verification of components. Fully operational in April 2010, SDO will provide images with a clarity 10 times better than HDTV. Data were available after a series of settings including turning on the Ka-band transmitter, which allowed the instrument to begin its scientific observations in mid-May 2010. During the mission, engineers will collect scientific data more complete and faster than any other spacecraft in solar observation. SDO is designed to help us understand the Sun's influence on the Earth and Earth space and study of the solar atmosphere will in many wavelengths simultaneously.
SDO has 10 CCDs, including 8 within the scientific instruments and in the two star trackers.
CCD sensors can operate at very low temperatures down to -100°C.
These high quality CCD sensors in visible light are designed for the detection of extreme ultraviolet light. They are cooled and protected from the sun by a panel radiators. The thermal radiation of the panel is enough to send into space the small amount of heat generated by the use of CCD sensors.


The exceptional activity of the Sun's April 5, 2010 has affected our satellite fleet. The Galaxy 15 satellite has stopped responding to commands and engineers to undertake a maneuver of recovery.

NB: The GSO or geosynchronous orbit is a geocentric orbit on which a satellite moves in the same direction as the Earth (from west to east) and whose orbital period is equal to the sidereal rotation period of land (approximately 23 h 56 min 4.1 s).
This orbit has a semi-major axis of about 42 200 km. If the orbit is located in the plane of the equator, the satellite appears as a fixed point in the sky.
It is then called "geostationary".
The geostationary orbit is a geosynchronous orbit has an inclination and zero eccentricity.
If the orbit is inclined to the plane of Earth's equator, the satellite describes a analemma in the sky when viewed from a fixed point on the Earth's surface.

Image:  Ring of Fire March 30, 2010. The Solar Dynamics Observatory image shows in detail a massive eruption that produced this great solar prominence taken on or about March 30, 2010.
The twisting motion of the solar material on this picture is the most remarkable feature.
Image Credit: NASA / SDO / AIA

 solar prominence, Ring of Fire March 30, 2010

Sunspot in September 2011


A sunspot group (AR numbered 1302) was visible to the naked eye in September 2011. There are over 400 years, March 9, 1611, the German student Johannes Fabricius, shows that the spots belong to the Sun. Fabricius, after a series of observations at the telescope, note that the spots are solar, as they travel over the day, around the western edge of the Sun. Fabricius concluded that the Sun rotates around its axis. Sunspots (4 000°) are visible because they are cooler than the Sun's surface (6 000°). At the end of solar cycle, sunspots, more numerous, are close to the solar equator. Cycle No. 24 will peak in 2012. In late September 2011, sunspots were visible to the naked eye at sunrise, while the brightness is even bearable for the eye.


These spots are also accompanied by prominences. Prominences are filaments of solar material, projected above the surface and characterizing the activity of the Sun. They can reach as March 30, 2010, the impressive size of 230 000 km (17 times the diameter of the Earth), the Sun's diameter is 1 392 000 km. These mass ejections cause beautiful auroras on Earth.

Image: This exceptional image taken from the Netherlands, with a telescope of 250 mm in diameter, shows the alignment of sunspots of September 25, 2011, numbered group AR 1302. This group has reached 150 000 km long. Image Credit: Emil Kraaikamp/

 sunspot AR1302 September 2011

Transit between SDO and Sun


During the transit of Venus of June 6, 2012, European observers were particularly disadvantaged because this transit took place between 0:10 ET 6:50 pm Paris time (10:10 p.m. 4:50 Universal Time). The sun was below the horizon. Venus appeared black, perfectly round and sharply defined on shiny background. Transits of Venus are the rarest eclipses visible from Earth, much rarer than eclipses of the Sun by the Moon or Mercury. The last transit of Venus before 2117, was one of the celestial phenomena the most photographed plenty of history. This live image of the Sun is taken by the SDO satellite.

Image: Venus moved between NASA’s Solar Dynamics Observatory, or SDO, and the sun. Image Credit: NASA / SDO & the AIA, EVE, and HMI teams.

 Transit de Vénus du 5 et 6 juin 2012 Lunar transit Jan. 30, 2014

Image: On Jan. 30, 2014, the moon moved between NASA’s Solar Dynamics Observatory, or SDO, and the sun, giving the observatory a view of a partial solar eclipse from space. Such a lunar transit happens two to three times each year. This one lasted two and one half hours, which is the longest ever recorded. Credit: NASA/SDO.

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