11/10/02 Solar Activity : The Sun was relatively quiet for much of the week,
and there was a period of about 2 days when activity was extremely low,
allowing RHESSI to work with the shutters out for long periods. There were only
2 M-class flares before Monday, and 63 C-class flares (17 above C5, 6 above C7).
Fortunately, RHESSI managed to catch the entire rise phase of the M4.6 flare on
9 Nov 2002 (15-minute rise period, 28-minute duration), and the entire M2.4
flare on 10 Nov 2002 (17-minute rise period, 31-minute duration).
11/10/02 SpaceWeather News:
AURORA WATCH: On Nov. 9th, an M4-class explosion near sunspot 180 hurled a
lopsided coronal mass ejection toward Earth. Sky watchers should be alert for
auroras on Nov. 11th or 12th when the cloud sweeps past our planet. (Courtesy
SpaceWeather.com)
10/31/02 RHESSI Update:
We are pleased to report that as of October 31, 2002, RHESSI has achieved its Minimum Science Requirements: 1. Perform hard X-ray (greater than 20 keV) imaging spectroscopy of solar flares with better than 4 arcsecond spatial resolution and better than 3 keV energy resolution. 2. Perform high resolution (better than 3 keV FWHM at l MeV) spectroscopy of gamma-ray lines in solar flares. 3. Obtain observations of at least a hundred hard X-ray flares and ten gamma-ray (greater than 300 keV) flares. RHESSI has performed imaging spectroscopy of hard X-ray flares from 3 keV upward, with 2.3 arcsec resolution, and ~1 keV energy resolution. It has obtained high resolution spectra of gamma-ray lines in the 23 July 2002 flare. On October 31, 2002, it detected its tenth gamma-ray (>300 keV) flare. It has also detected over one thousand hard X-ray (>25 keV) flares. All systems are operating nominally, and we are looking forward to eventually achieving the Baseline Science Requirements. Best regards, Bob Lin, Brian Dennis, and the RHESSI team
August 2002 RHESSI in the News:
In the August 2002 Issue of Astronomy magazine there was a brief news article
about RHESSI: "New Probe of the Sun," by Richard Talcott.
Click Here to read the article. Reproduced by permission. Copyright 2002
Astronomy magazine, Kalmbach Publishing Company.
07/28/02 SpaceWeather News:
The
Boulder sunspot number reached its highest value in more than a year this
weekend;the sun is peppered with spots. On Friday, an explosion near one of
them--giant sunspot 39--hurled a coronal mass ejection (CME) into space.
Although the CME was not squarely Earth-directed, some of the cloud is heading
our way. It could sweep past Earth as early as Sunday, July 28th, and trigger
geomagnetic activity. Sky watchers should be alert for auroras after nightfall.
07/19/02 SpaceWeather News:
Sunspot 30
remains impressive. It stretches 15 Earth diameters from end to end. A second
spot (active region 36) has grown nearly as large in recent days. You can
see both--but NEVER STARE DIRECTLY AT THE SUN.
07/16/02 SpaceWeather News:
A
remarkable sunspot is crossing the face of the Sun. The large active region
stretches 15 Earth-diameters from end-to-end and poses a threat for powerful
flares. Indeed, on July 15th, twisted magnetic fields above the spot erupted.
The explosion sparked an X-class solar flare and hurled a coronal mass ejection
into space. As a result, sky watchers on Earth might spot auroras on Tuesday or
Wednesday night.
06/09/02 SpaceWeather News:
SOLAR BLAST: The ESA/NASA Solar and Heliospheric Observatory recorded an
unusually beautiful eruption on the Sun today. The giant "prominence" was bigger
than 50 planet Earths from end to end. Visit SpaceWeather.com and see for
yourself.
Also, DON'T FORGET THE SOLAR ECLIPSE! Across much of North America on Monday,
June 10th, the setting Sun will become a strange-looking crescent when the Moon
glides in front of our star. Follow the links at SpaceWeather.com for more
information, including eclipse-safe observing tips.
WARNING: Never stare directly at the Sun. And never, ever look at the Sun
through an unfiltered telescope. Even during an eclipse the Sun can damage your
eyes.
06/07/02 RHESSI in the News:
New York Times repoter John Noble Wilford has written an article about some of
the latest findings from RHESSI: Close-Up
Views of Sun Give Astronomers More to Think About (Free Registration is
Required to view the article).
04/21/02 SpaceWeather News:
A BIG SOLAR BLAST:
An
explosion on the Sun today sparked a powerful X-class solar flare and hurled a
coronal mass ejection (CME) into space.
Although the CME was not squarely Earth-directed, the expanding cloud will
likely deliver a glancing blow to Earth's magnetosphere on April 22nd or 23rd.
Sky watchers should remain alert for renewed geomagnetic activity and auroras.
04/01/02Spaceflight Now on line spaceflight news.
02/26/02 First Images of RHESSI
FIRST
RHESSI Image
No smoke without a fire! The RHESSI satellite observed the
‘fire’ of a solar flare for the first time, whereas the ‘smoke’ in the form of
coronal mass ejections is well-known. The red-yellow spot marks the fire that
brightened up on the Sun on February 26, 10.26 GMT for a minute. It originated
from a gas having a temperature of 200 million degrees and a diameter a third of
Earth's. It marks the place where thirty thousand times the European electricity
consumption of the year 2001 was released.
RHESSI Movie Clip
A sequence of images like the one above is also available
in movie form. The high-energy radiation appears only briefly, during the phase
of actual energy release.
02/21/02 Space Weather News
www.spaceweather.com - movie 1
www.spaceweather.com - movie 2
Solar activity intensified on Feb. 20th and 21st when sunspot magnetic fields
erupted several times, producing a series of M-class solar flares.
At least one of the eruptions also hurled a coronal mass ejection (CME) toward
our planet. Sky watchers at high latitudes -- e.g., northern Europe, Canada, and
across the northern tier of US states -- should be alert for Northern Lights
late Friday (Feb 22) or Saturday (Feb 23) when the CME will likely sweep past
Earth.
02/06/02The
Biggest Explosions in the Solar System-
NASA's RHESSI spacecraft aims to unravel an explosive mystery: the origin of
solar flares.
02/05/02 "Sun Cranks our Rare Cookie Cutter Flares" from GSFC Top Story.
02/05/02
RHESSI Launch Day-
New UC Berkeley/NASA x-ray spacecraft heads for the sun after Feb. 5 launch.
02/05/02 Live Video from Cape Canaveral Pegasus Launch
02/05/02 RHESSI participation atNASA Connect's
Having a Solar Blast program for educators. Starts airing: Thursday, March 28, 2002, 11 am ET. The associated activity guide will be helpful in completing the lesson01/18/02 "Resurgent Sun" from Science@ NASA
Last updated 02/01/2010 © UC Regents