Expert: Philip Stahl - 4/13/2009

Question
QUESTION: I am a amature astronomist. While viewing the son in Feb. of this year, I keep seeing something I do not understand. I will attach an image, but for reference, I keep seeing what looked like a small hole at the edge of the sun. I have asked several people, but no one could explain it. Could you possibly identify what they are. They only last a few seconds and then disappear.

ANSWER: Hello,

It really isn't possible to say very much without knowing many more details of the observation. For example, what time did you make the observation? What were the observing conditions (cloudy, all clear, haze etc.)?

What instrument did you use? (Telescope, aperture? - Focal length?) Did you use a solar filter (e.g. Solar Skreen) or did you project the image?

Until all the relevant observing details are known, including your instrument, I can't be of much help.



---------- FOLLOW-UP ----------

QUESTION: I am sorry I did not enclose that information the first time. I am new to astronomy and 65 yrs. old.
The following is the information you need;

Observation Information:

Date, Feb. 17, 2009, 1400 Local w/-7 UTC
Clear Sunny day
Observation Point; Lat. = 32, 48, 16 N
         Lon. = 105, 58, 53 W

Telescope Type; Meade DS-2114ATS-TC
Focal Length; 1000mm, clear Aperture = 114mm
Focal Ratio; f8.8, Reflector

Using: Solar Filter Sheet, Neutral Density = 5, Orange Color
From: Seymour Solar.

Observation appeared and would disapper in between 5 to 10 seconds. I observed several eppisodes ( 10 to 15 )

I hope this all helps, I would really like to know if I observed something new or what.

Answer
Thanks for your observing information. I just wanted that to be able to rule out any atmospheric or "system" effects.

I think the following link will prove useful for you, especially since your "hole" occurred at in the vicinity of the solar limb:

http://www.solarphysics.kva.se/highlights/faculae-explained/

Excerpt:

"Observations with the SST *close to the limb* (See image to the left, observer Göran Scharmer, Institute for Solar Physics (ISP)) for the first time demonstrated that the solar surface is **not flat but a 3D structure with "hills" and "valleys" directly associated with solar granules**, the tops of giant convection cells in the solar atmosphere Lites et al. (2003) used a subfield to measure the depression of an umbra compared to one of the light bridges"

Hope this sheds light!