Archive for December, 2011
After leaving SDO/AIA’s field of view, Comet Lovejoy re-appeared in the field-of-view of SOHO’s LASCOs coronagraph:
Comet Lovejoy has been spotted coming out from behind the disk of the Sun:
As seen by SDO/AIA in 171 angstroms.
We just uploaded an early movie of Comet Lovejoy as seen by SDO/AIA 171 angstroms.
It’s a bit short, but we hope you like it! It’s only the second time a comet has been seen with SDO!
Want Comet Lovejoy on your desktop….?
Because of the increased interest in solar images caused by the appearance of Comet Lovejoy, Helioviewer.org users may need to wait for longer than usual in order to create a movie.
JHelioviewer is a related effort to Helioviewer.org and provides support for accessing many of the same images as Helioviewer.org including LASCO and AIA, via a desktop application. Try it out and let us know what you think.
Comet Lovejoy will be passing close to the Sun in the next couple of days. SDO will be taking special observations of the comet beginning 22:59 UT on 2011/12/15 (5.59pm 2011/12/15, Eastern Time), and lasting for a couple of hours. The comet will pass behind the solar limb at around 00:07 UT 2011/12/16 (7:07pm 2011/12/15, Eastern Time). There is a chance the comet will survive its encounter with the Sun.
SDO/AIA will take special observations to view the comet; AIA will change its pointing and point slightly away from the center of the Sun in order to try to get more observations of the comet as it gets close to the disk of the Sun.
Why are these observations being taken? Well, we are looking for something like we saw on 2011/07/05 this year. On that day a comet fell in to the Sun. These kinds of comets have been seen before in LASCO-C3 and LASCO-C2 images. What was new about this observation was that for the first time the comet was seen against the disk of the Sun. The video below gives a description of what was seen.
SDO/AIA detects different wavelengths of light. So in order for us to see it, the comet must have been emitting at those different wavelengths, and the comet must have disintegrated in to a big enough cloud of ionized gas for us to see it. So the big scientific question about seeing this comet against the disk of the Sun is explaining both how it came to be emitting at wavelengths that SDO/AIA could see, and figuring out how it could have disintegrated. This is an active area of research, with presentations on this subject given last week at the American Geophysical Union‘s Fall Meeting, and a paper set to appear in Science.
We hope you enjoy tracking Comet Lovejoy as it gets closer to the Sun. Please let us know if you have any further questions about the Helioviewer Project and Comet Lovejoy.
A new version of Helioviewer.org has been released, including a few new features to make it easier to share videos and links.
Helioviewer.org 2.2.2 is an incremental release. This release is focused on sharing. Buttons have been added below movies to make it easier to share the movie on Facebook, Twitter, etc and optional link-shortening has been included for both Helioviewer.org and movie URLs using bit.ly. Another new feature is a visual glossary. While still a work in progress, the glossary aims to help make it easier to find out what the different terms used on Helioviewer.org, and also help determine what a partcular feature or event is.
Let us know what you think, or if you have any suggestions. Feedback is always welcome.
* Easy sharing on Facebook, Twitter, etc. using AddThis
* Added a visual glossary of solar terms
* URL shortening via bit.ly
* Download source JPEG 2000 images associated with an image layer
* It’s now possible to create 1-hour or 28-day movies
* Fixed bug #890721 Prevent redundant videos from being uploaded to YouTube
* Fixed bug #887154 Have links shared on Facebook use relevant thumbnail.
* Fixed bug #887634 Add a cap to video queue to avoid excessive wait times during heavy usage
* Fixed bug #887152 Fix an issue causing zoom slider to be improperly initialized
* Fixed bug #888270 Prevent flash video player from blocking movie links
* Fixed bug #888585 Escape square brackets in Helioviewer.org links to enable better automatic hyperlinking
* jQuery (1.6.4 => 1.7)
* jQuery Mousewheel (3.0.2 => 3.0.6)