Friday, October 9, 2015

SDO Website is back up

The maintenance on the SDO web and data servers is complete the website is back up and running normally. Thank you.

SDO website is undergoing maintenance

The SDO web and data servers are undergoing maintenance and will be unavailable for a time. We apologize for any inconvenience. We will send out a message as soon as our servers are back up.

Wednesday, October 7, 2015

The First Maneuver of the First SDO Extended Mission

On October 1, 2015, SDO began the First SDO Extended Mission. The SDO Team submitted a proposal to NASA in March to continue observing the Sun for another two years. The proposal was approved and we began the extended mission on October 1.

With the extended mission comes calibration maneuvers. The first is an EVE cruciform today from 1800 UTC (2:00 p.m. ET) until 2230 UTC (6:30 p.m. ET). SDO science data will not available during the maneuver but the AIA images on the SDO website will look like the Sun is zooming around in space.

Congratulations to the SDO Team for the successful proposal and winning another two years of watching the Sun and solar activity!

Monday, September 14, 2015

Movies of the Alignment at NASA

NASA has posted a feature about the alignment yesterday morning. It looks great!
Check it Out!

I made a short video from the AIA jpeg2000 images. You can also make these movies at HelioViewer. The motion of the Sun is caused by the telescope heating up as the Sun rises. SDO cannot run its fine guidance system without seeing the entire Sun. During an eclipse the fine guidance system is turned off and a little while after the eclipse it is turned back on.

Friday, September 11, 2015

An Alignment of the Four Most Important Objects in the Solar System

Sunday morning, September 13, 2015, we will have an alignment of the four most important objects in the solar system. SDO, the Earth, the Moon, and the Sun will form a line in space. From 0614 UTC (2:14 a.m. ET), when the Earth's edge touches the edge of the Sun, until 0721 UTC (3:21 a.m. ET), when the Moon's edge leaves the Sun, SDO's field of view will be blocked by either the Earth or Moon. The attached movie was produced by the SDO flight operations team to show how the eclipse and lunar transit will look from SDO. This is the first time an eclipse by the Earth and a lunar transit will be seen by SDO. (Although we can see features on the Earth and Moon in the video, we cannot see them in the SDO cameras.)

But that's not all! At 0655 UTC (2:55 a.m. ET) a partial solar eclipse will be visible in Antarctica. The path of the solar eclipse starts in southwestern Africa and goes almost over the South Pole. On the left is a picture from NASA's Eclipse webpage showing the path of the solar eclipse. This is the first time a solar eclipse was visible on the Earth during an SDO lunar transit. SDO cannot see the entire solar eclipse because the Earth gets in the way. The Moon was at perigee (closest point to the Earth) for the Full Moon two weeks ago. That means it is at apogee (furthest point from the Earth) for the New Moon on Sunday. The Moon will appear to be a little smaller than average so a total solar eclipse is not possible this month.

On September 28, 2015 a total lunar eclipse will be visible from most of the United States, Europe, South America and Africa. SDO does not see lunar eclipses because we look the other way. Not to worry, SDO will see another Lunar Transit on October 12, 2015 from 1718 – 1733 UTC (1:18 – 1:33 p.m. ET). It will be a grazing transit. Because SDO will not be near midnight Mountain Time, this transit will not be seen at the surface.

I hope you enjoy the Alignment of the Four Most Important Objects in the Solar System.

Friday, August 28, 2015

Comet has Faded

The incoming sungrazing comet has faded and will most likely not be visible this afternoon in SDO AIA images. This is common in Kreutz comets, they evaporate before reaching the Sun. The light curve looks like a small comet evaporating.

Here's the latest from Karl Battams: "As I expected, the comet "pulled an ISON". I won't even describe it as a comet any longer. It's a rubble pile." (SunGrazerComets).

The Comet is Still There, Waiting for the Perihelion Time Update

This morning we should get better information about the orbit of the incoming comet. The orbit from last night is shown at left (times are in UTC). The plus signs are spaced 5 minutes apart. They get a little farther apart as the comet moves from lower right to the upper left. This means the comet is speeding up. At perihelion (the closest it gets to the Sun) the comet will be moving at about 600 km/s (1.3 million mph).

We see comets because they evaporate ices and other compounds from their surface. This cools the comet, but makes it disappear. The water ice that comes off the comet quickly turns into Hydrogen and Oxygen atoms. SDO sees comet tails when the oxygen atoms hit the electrons in the corona. We can use the tails to explore the Sun's magnetic field and corona.

Most Kruetz sungrazing comets are too small to make it to perihelion (Comet Lovejoy in December 2012 was the only exception). We can only watch as this comet goes behind the LASCO occulter disks and hope it continues to evaporate and be seen in SDO/AIA images.