Astrophotography by Anthony Ayiomamitis

Solar Image Gallery - Prominences in H-alpha

The sun's outermost "shell", the chromosphere, is a region measuring approximately 2000 km deep and is the source of some incredibly dynamic activity and temperatures reaching 400,000 C at its furthest distance from the photosphere and is not visible to the naked eye or telescope filtered with typical mylar white-light material. Although the latter provides interesting views of the solar disk and the various sunspots and sunspot groups (see here) with some granulation during moments of good seeing, H-alpha filters add a totally new dimension to our closest star as they permit for the observation and imaging of the glowing red hydrogen gas which makes up nearly 80% of the sun. Violent explosions and outbursts involving the hydrogen gases and the process of nuclear fusion of hydrogen to helium lead to the development of filaments, flares and prominences. For the former, one will observe typically dark patches of red on the solar limb as a result of the trapped gases. In contrast, flares and prominences represent ejected material which can reach distances of up to 2 million kilometers from the sun.

Filaments and prominences are typically characterized as Class I ("Quiescent Filaments and Prominences") or Class II ("Active Filaments and Prominences"). For the former, they can last for a few months and typically show little activity from day-to-day. In contrast, the latter are much more dynamic and short-lived, may even last for only a few hours and often produce, for example, very beautiful "flare loops" and "coronal rains".


Image Details
Prominence(s) in H-alpha
Imaging Details
Body:
Sun

Mass:
332,900 x Earth

Mean Eq Diameter:
109.1 x Earth

Distance:
152 million km

RA / Dec:
04h 35m 42s /
22 01' 34"


Diameter:
31.48'

Magnitude:
-26.8
Date:
June 01, 2003
13:20:27 UT+3


Location:
Athens, Greece

Equipment:
TeleVue Pronto Refractor
Nikon Coolpix 995
ScopeTronix STWA14 Adapter
Coronado SolarMax 60
Coronado T-Max 60
Coronado BF10


Exposure(s):
1/8 sec @ f10
ISO 200
JPG RGB Fine image format
2048x1536 image size
Autodark subtraction


Software:
Photoshop V6

Processing:
Despeckle
Contrast/Brightness
Unsharp Masking
Levels
Layers