You are viewing the page for May. 17, 2013
  Select another date:
<<back forward>>
SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids Internet Shopping Sites high quality binoculars excellent weather stations all-metal reflector telescopes rotatable microscopes
 
Solar wind
speed: 399.1 km/sec
density: 4.8 protons/cm3
explanation | more data
Updated: Today at 2347 UT
X-ray Solar Flares
6-hr max: B8
1707 UT May17
24-hr: M3
0858 UT May17
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 17 May 13
Sunspot AR1748 has a delta-class magnetic field that harbors energy for X-class solar flares. Credit: SDO/HMI
Sunspot number: 212
What is the sunspot number?
Updated 17 May 2013

Spotless Days
Current Stretch: 0 days
2013 total: 0 days (0%)
2012 total: 0 days (0%)
2011 total: 2 days (<1%)
2010 total: 51 days (14%)
2009 total: 260 days (71%)
Since 2004: 821 days
Typical Solar Min: 486 days

Update
17 May 2013

The Radio Sun
10.7 cm flux: 145 sfu
explanation | more data
Updated 17 May 2013

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/POES
Planetary K-index
Now: Kp= 3 quiet
24-hr max: Kp= 3
quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 8.0 nT
Bz: 5.5 nT south
explanation | more data
Updated: Today at 2347 UT
Coronal Holes: 17 May 13
There are no large coronal holes on the Earthside of the sun. Credit: SDO/AIA.
SPACE WEATHER
NOAA Forecasts
Updated at: 2013 May 17 2200 UTC
FLARE
0-24 hr
24-48 hr
CLASS M
75 %
75 %
CLASS X
50 %
50 %
Geomagnetic Storms:
Probabilities for significant disturbances in Earth's magnetic field are given for three activity levels: active, minor storm, severe storm
Updated at: 2013 May 17 2200 UTC
Mid-latitudes
0-24 hr
24-48 hr
ACTIVE
15 %
35 %
MINOR
05 %
30 %
SEVERE
01 %
20 %
High latitudes
0-24 hr
24-48 hr
ACTIVE
15 %
05 %
MINOR
25 %
20 %
SEVERE
25 %
75 %
 
Friday, May. 17, 2013
What's up in space
 

Listen to radar echoes from satellites and meteors, live on listener-supported Space Weather Radio.

 
Spaceweather Radio is on the air

POSSIBLE CME IMPACT ON MAY 17: A coronal mass ejection (CME) hurled into space by the X1-flare of May 15th might deliver a glancing blow to Earth's magnetic field on May 17th. NOAA forecasters estimate a 40% chance of polar geomagnetic storms when the cloud arrives. High-latitude sky watchers should be alert for auroras tonight. Aurora alerts: text, voice.

M3-FLARE: Sunspot AR1748 unleashed an M3-class solar flare on May 17th at 0858 UT: image. Although this is not the strongest flare we've seen from AR1748, it could be the most geoeffective. The sunspot is facing Earth more directly than before, and the explosion might have hurled a CME toward our planet. Stay tuned for updates. Solar flare alerts: text, voice.

To illustrate the scale of the sunspot, photographer Göran Strand of Frösön, Sweden, inserted Earth into a picture of AR1748 he took on May 16th:

The sunspot's primary dark cores are nearly as big as our planet. However, that doesn't make this a big sunspot. Other 'spots on the sun today are larger. AR1748 is not explosive because it is large, but rather because it has a complex magnetic field. Lines of magnetic force twisting above the spot are criss-crossing and re-connecting. That's how you make an X-flare.

All by itself, AR1748 has produced more X-flares than every other sunspot of the past year combined. In summary, AR1748 has given us an X1.7-class flare (0217 UT on May 13), an X2.8-class flare (1609 UT on May 13), an X3.2-class flare (0117 UT on May 14), and an X1-class flare (0152 on May 15). Solar flare alerts: text, voice.

Realtime Space Weather Photo Gallery

DISCONNECTION EVENT IN THE TAIL OF COMET LEMMON: Comet Lemmon (C/2012 F6), which is receding from the sun not far beyond the orbit of Earth, has just experienced a "disconnection event." A cloud of dusty plasma is propagating down the comet's tail, shown here in a photo taken by Paul Mortfield on May 15th:

"I was pretty surprised to see this disconnection event when I processed the images," says Mortfield. "The comet is a challenge to photograph because it is so low in the sky at the start of morning twilight."

Disconnection events can be caused by CME impacts. A famous example is that of Comet Encke in 2007. Comet Lemmon, however, is not on the same side of the sun as active sunspot AR1748. It's hard to see how the recent X-flares can be responsible. Nevertheless, solar activity is high, so now is a good time to monitor comet tails. They are very sensitive to stormy space weather.

Comet Lemmon is a pre-dawn object for observers in the northern hemisphere. It is currently gliding alongside the Great Square of Pegasus in the eastern sky before sunrise. The 7th-magnitude comet is too faint to see with the naked eye, but it is visible in medium-to-large backyard telescopes. Observers with computerized GOTO 'scopes should point their optics here.

More about Comet Lemmon: 3D orbit, ephemeris, light curves.

Realtime Comet Photo Gallery


Realtime Aurora Photo Gallery


Realtime Noctilucent Cloud Photo Gallery
[previous years: 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2011]

  Near Earth Asteroids
Potentially Hazardous Asteroids (PHAs) are space rocks larger than approximately 100m that can come closer to Earth than 0.05 AU. None of the known PHAs is on a collision course with our planet, although astronomers are finding new ones all the time.
On May 17, 2013 there were potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Asteroid
Date(UT)
Miss Distance
Size
2013 JM22
May 16
7.9 LD
95 m
2004 BV102
May 25
69.9 LD
1.4 km
1998 QE2
May 31
15.2 LD
2.1 km
2009 FE
Jun 4
9.6 LD
230 m
2000 FM10
Jun 5
50.3 LD
1.3 km
2002 KL3
Jun 6
66.4 LD
1.1 km
1999 WC2
Jun 12
39.2 LD
1.9 km
2006 RO36
Jun 18
70.9 LD
1.2 km
2001 PJ9
Jul 17
29.2 LD
1.1 km
2006 BL8
Jul 26
9.3 LD
48 m
2003 DZ15
Jul 29
7.6 LD
153 m
2005 WK4
Aug 9
8.1 LD
420 m
Notes: LD means "Lunar Distance." 1 LD = 384,401 km, the distance between Earth and the Moon. 1 LD also equals 0.00256 AU. MAG is the visual magnitude of the asteroid on the date of closest approach.
  Essential web links
NOAA Space Weather Prediction Center
  The official U.S. government space weather bureau
Atmospheric Optics
  The first place to look for information about sundogs, pillars, rainbows and related phenomena.
Solar Dynamics Observatory
  Researchers call it a "Hubble for the sun." SDO is the most advanced solar observatory ever.
STEREO
  3D views of the sun from NASA's Solar and Terrestrial Relations Observatory
Solar and Heliospheric Observatory
  Realtime and archival images of the Sun from SOHO.
Daily Sunspot Summaries
  from the NOAA Space Environment Center
Heliophysics
  the underlying science of space weather
Space Weather Alerts
   
  more links...
©2010 Spaceweather.com. All rights reserved. This site is penned daily by Dr. Tony Phillips.
©2019 Spaceweather.com. All rights reserved.