Cap'n Bob & the Damsel

Astronomy

Solar Eclipse as Seen From SDO

sdo-transit.jpgAn Interesting eclipse occurred earlier this month when the moon passed between the Solar Dynamics Observatory and the Sun. This is the first recorded lunar/solar eclipse taken by SDO although earth/solar eclipses happen often. SDO is like the Hubble Space Telescope but is totally devoted to solar activity.

The image at the right shows the partially-eclipsed solar disk (courtesy NASA – click to enlarge). I also uploaded a close-up image in which the mountains along the lunar limb can be discerned against the solar disc. This demonstrates the excellent resolution of the instruments aboard SDO.

The following is taken from the SDO website where you can download and watch a Quicktime video of the eclipse.

This was a first for SDO and it was visually engaging too. On October 7, 2010, SDO observed its first lunar transit when the new Moon passed directly between the spacecraft (in its geosynchronous orbit) and the Sun. With SDO watching the Sun in a wavelength of extreme ultraviolet light, the dark Moon created a partial eclipse of the Sun.

These images, while unusual and cool to see, have practical value to the SDO science team. Karel Schrijver of Lockheed-Martin’s Solar and Astrophysics Lab explains: “The very sharp edge of the lunar limb allows us to measure the in-orbit characteristics of the telescope e.g., light diffraction on optics and filter support grids. Once these are characterized, we can use that information to correct our data for instrumental effects and sharpen up the images to even more detail.”

18 Oct 2010 by Aerospace Astronomy Rocket Science

Solar “Conveyor Belt” Speeds Up

This is an interesting article on the SOHO website. The speeding of the internal plasma circulation is connected with the deepest solar minimum in a century.

solar conveyorOne of the outstanding questions facing solar physicists is the origin of the solar magnetic cycle: What drives the 11-year sunspot cycle? We have just passed an extended and deep minimum, unlike any in the past 100 years. The late onset of the new solar cycle (#24) and the unusually deep minimum between cycles 23 and 24 took all experts by surprise, which suggests that there is a fundamental lack in our understanding of the origin of the solar activity cycle.

Image: Artist’s concept of the Sun’s meridional circulation, a large scale flow that transports solar plasma from the equator to the poles and back like a giant conveyor belt. Credit: Science@NASA

The Sun’s meridional circulation is a massive flow pattern within the Sun that transports hot plasma near the surface from the solar equator to the poles and back to the equator in the deeper layers of the convection zone, similar to a “conveyor belt”. The flow is rather slow, with typical speeds of 10-15 m/s (20 to 30 mph). The structure and strength of this meridional flow is believed to play a key role in determining the strength of the Sun’s polar magnetic field, which in turn determines the strength of the sunspot cycles. One class of dynamo models predicts that a stronger meridional flow produces weaker polar fields, whereas another class of models predicts stronger polar fields (and a shorter sunspot cycle) for the same flow. [more]

08 Jul 2010 by Astronomy Environment Science

Fathers Day Flare

The new solar cycle antes up a massive CME for Fathers day. From SpaceWeather.com . . .

FATHER’S DAY BLAST: Consider it a Father’s Day gift … from the sun. This morning around 1 a.m. UT, magnetic fields on the sun’s eastern limb became unstable and erupted, producing one of the most spectacular explosions of the year. NASA’s Solar Dynamics Observatory recorded the action:

The explosion did not cause a solar flare (a flash of electromagnetic radiation) but it did hurl a massive cloud of magnetized plasma into space. Because of the blast site’s location on the eastern limb, the cloud will not hit Earth. There won’t be any geomagnetic storms or auroras.

20 Jun 2010 by Aerospace Astronomy Science

STEREO Spacecraft Approaching Diametric Opposition

Why would that be significant? Well, it would allow for a full 4PI (360×360°) view of the sun. The animated movie of the sun on STEREO’s Website currently has a gap in the coverage of the sun. The spacecraft are in a heliocentric orbit drifting away from the Earth, one leading and one lagging. This diagram shows the current position of spacecraft A (ahead) and B (behind). The scale is in astronomical units, the average distance between the earth and sun.

Sun-monitoring instrumentation on spacecraft like SOHO and STEREO have gone a long way in discovering what makes the sun behave in mysterious ways. Also, the data coming back (when not intentionally distorted by the IPCC, the CRU or NASA’s James Hansen) can be used to chart the relationship between solar activity and global climate.

stereo.jpg

16 Jun 2010 by Aerospace Astronomy Global Warming Science

First Light for the Solar Dynamics Observatory

These images are just astounding . . .

prom.jpgApril 21, 2010: Warning, the images you are about to see could take your breath away.

At a press conference today in Washington DC, researchers unveiled “First Light” images from NASA’s Solar Dynamics Observatory, a space telescope designed to study the sun.

“SDO is working beautifully,” reports project scientist Dean Pesnell of the Goddard Space Flight Center. “This is even better than we could have dreamed.”

Launched on February 11th from Cape Canaveral, the observatory has spent the past two months moving into a geosynchronous orbit and activating its instruments. As soon as SDO’s telescope doors opened, the spacecraft began beaming back scenes so beautiful and puzzlingly complex that even seasoned observers were stunned.

Be sure to click on the image above to view full-size and then go to the SDO Website.

21 Apr 2010 by Astronomy Rocket Science

Categories

Archives