Sun Clouds

Better known as solar prominences or filaments, Prominences are dense clouds of material suspended above the surface of the Sun by loops of magnetic field.

Image by J P Brahic

Prominences and filaments are actually the same things except that prominences are seen projecting out above the limb, or edge, of the Sun. Both filaments and prominences can remain in a quiet or quiescent state for days or weeks. However, as the magnetic loops that support them slowly change, filaments and prominences can erupt and rise off of the Sun over the course of a few minutes or hours. [**]

Manhattanhenge is when the sunset aligns perfectly with the city’s grid. This happens twice a year with a full sun, and twice a year with a half sun—all four times the sun illuminates both the north and south sides of every cross street of the borough’s grid. It is our Stonehenge, and deGrasse Tyson has declared it to be “a unique urban phenomenon in the world, if not the universe.”

Tips from NdT: “Position yourself as far east in Manhattan as possible. But ensure that when you look west across the avenues you can still see New Jersey. Clear cross streets include 14th, 23rd, 34th. 42nd, 57th, and several streets adjacent to them. The Empire State building and the Chrysler building render 34th street and 42nd streets especially striking vistas.”

Half Sun on the Grid

Friday, May 29 8:12 P.M. EDT
Monday, July 13 8:21 P.M. EDT

Full Sun on the Grid

Saturday, May 30 8:12 P.M. EDT
Sunday, July 12 8:20 P.M. EDT


Sun Unleashes 1st Major Solar Flare of 2014

A massive solar flare erupted from the sun on Tuesday (Jan. 7), rising up from what appears to be one of the largest sunspot groups seen on the star’s surface in a decade, NASA officials say.

Image: This NASA view combines two images from NASA’s Solar Dynamics Observatory captured on Jan. 7, 2014. Together, the images show the location of a giant sunspot group on the sun, and the position of an X-class flare that erupted at 1:32 p.m. EST. Credit: NASA/SDO

Solar Halo by César Cantú

Halo is an optical phenomenon produced by ice crystals creating colored or white arcs and spots in the sky.

Many are near the sun or moon but others are elsewhere and even in the opposite part of the sky. They can also form around artificial lights in very cold weather when ice crystals called diamond dust are floating in the nearby air.


Huge Solar Flare Erupts from Biggest Sunspot in 24 Years

The biggest sunspot on the face of the sun in more than two decades unleashed a major flare on Friday (Oct. 24), the fourth intense solar storm from the active star in less than a week.

Image 1: This full-disk image of the sun shows the location of the major X3.1 solar flare on Oct. 24, 2014. The solar flare erupted from the largest sunspot on the sun in 24 years. Credit: NSA/SDO

Image 2: A massive X3.1 solar flare erupts from the giant sunspot AR 12192 on Oct. 24, 2014 in this close-up view from NASA’s Solar Dynamics Observatory, a spacecraft that constantly watches Earth’s nearest star. Credit: NASA/SDO

The solar flare occurred Friday afternoon, reaching its peak at 5:41 p.m. EDT (2141 GMT), and triggered a strong radio blackout at the time, according to the U.S. Space Weather Prediction Center. NASA’s sun-watching Solar Dynamics Observatory captured stunning video of the huge solar flare.

The flare erupted from a giant active sunspot known as AR 12192 and was classified as an X3.1-class solar storm — one of the most powerful types of solar storms on the sun — but it is not the first time the sunspot has made its presence known.

“This is the fourth substantial flare from this active region since Oct. 19,” NASA spokesperson Karen Fox wrote in a status update.


Solar prominence in CaK light (Calcium II K)

I present more awesome solarphotography and calcium filters from my friend Kokehtz / Álvaro for you to marvel at :)

Light from singly-ionized calcium ions in the Sun’s upper photosphere and chromosphere (up to 2000 km altitude). Because the blue Calcium K Line (393.3 nm) is sensitive to magnetic fields, magnetically active structures show up in high contrast against the surrounding chromosphere. Places where moderate magnetic fields exist show up bright whereas images of high magnetic fields are dark.

Image Copyright: Álvaro Ibáñez Pérez

In this CaK image, you typically see brightness along the edges of large convection cells called supergranules and in areas called plages. Dark sunspots are also visible.

Spots on the sun are areas of high magnetic field which appear dark to their surroundings (5,800K) due to their cooler temperature of around 3000-3500K. Spots consist of a dark central region (umbra) and are surrounded by an annular region of dark and bright filaments called the penumbra. Within a developing active region (sunspot group) tiny spots form initially without a developed penumbra and are called pores. These are usually relatively short lived or can develop a penumbra and become a fully developed spot.

The chromosphere is a place of high solar activity. In the course of a few minutes we can observe changes in the ejecta and prominences, in the path of the filaments, and as matter flows following very characteristic arches. Chromosphere is also visible in the light emitted by the ionized calcium, in the violet part of the solar spectrum in a wavelength of 393.4 nm. This light comes from calcium atoms that have lost an electron.