Naked eye Sunspots (2001/4/1)


Date & Time: Apr 1 2001, 10:58 JST(+0900), 1/500sec. Exp.
Optical: TAKAHASHI 12.5cm(4.9") fluorite refractor, afocal method with LV25mm eyepiece
Stopped down to 5cm(2"), with two ND400 filters
Synthesized focal length f=460mm (equivalent f=2465mm in 35mm film format)
Auto-guided with GOTO MX-II Equatorial
Digital Camera: OLYMPUS C-2020Z
Location: Ooizumi vil., Yamanashi pref.

Camera Settings: Mode.....SHQ (1600 x 1200, high-quality JPEG format)
Lens.....f=11.5mm (equivalent f=60mm in 35mm film format), Stop: F2.2
CCD sensitivity.....ISO100, White Balance.....Auto


The Sun had the sunspots activity in maximum in spring of 2000, we could observe rise and fall of many groups of sunspots. This activity continued in 2001, and we can see the largest sunspot group in last ten years in end of March. Its size reaches about 13 times of that of the Earth.
This picture shows you the huge sunspot group near the western edge of photosphere of the Sun. You could detect the sunspot group only with your naked eyes through light-reduction filters. I have displayed a close-up image of the sunspot group. You can appreciate various sized umbrae and surrounding penumbrae.
(This picture has been displayed by turning north direction upward)
Close-up image of sunspot group Close-up image of sunspot group

  The detailed structure of naked eye sunspots near the wester edge of the surface of Sun.
(afocal method with LV12mm eyepiece, Synthesized focal length f=1592mm, with ND400 filter)


Warning: When using a telescope for observing or photographing the sun, lacking knowledge of proper solar filtering methods can pose risks of visual impairment or blindness.
I do not assume any responsibility for any accidents that may occur as a result of observing or photographing the sun through this site.



Change of Solar surface in Jun 2007
The Sun

Copyright(c) 2001 by Naoyuki Kurita, All rights reserved.
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