LISTSERV mailing list manager LISTSERV 16.0

Help for ATM-OBSERVERS-L Archives


ATM-OBSERVERS-L Archives

ATM-OBSERVERS-L Archives


ATM-OBSERVERS-L@LISTS.UFL.EDU


View:

Message:

[

First

|

Previous

|

Next

|

Last

]

By Topic:

[

First

|

Previous

|

Next

|

Last

]

By Author:

[

First

|

Previous

|

Next

|

Last

]

Font:

Proportional Font

LISTSERV Archives

LISTSERV Archives

ATM-OBSERVERS-L Home

ATM-OBSERVERS-L Home

ATM-OBSERVERS-L  November 2011

ATM-OBSERVERS-L November 2011

Subject:

Sun Through Small Scope

From:

"Howard L. Cohen" <[log in to unmask]>

Reply-To:

Howard L. Cohen

Date:

Fri, 18 Nov 2011 17:25:19 -0500

Content-Type:

multipart/mixed

Parts/Attachments:

Parts/Attachments

text/plain (57 lines) , Sun.2011-11-10.jpg (57 lines)

The Solar Disk Is Not Blank Any More Even Through a Small Telescope

Some predictions say future sunspot cycles may show declining 
activity. However, the current cycle is gearing up with more 
sunspots, flares and coronal mass ejections than have been seen in 
several years. Even a good, small telescope (equipped with a safe 
solar filter) easily shows this.

On 2011 November 10, for example, I was helping my grandson earn his 
Cub Scout Belt Loop. One requirement is to set up and demonstrate how 
to focus a simple telescope. We set the telescope on the Sun. At 
least eight sunspot groups were visible with dozens of individual 
spots readily seen even through a three-inch refractor telescope from 
Gainesville, Florida.  (See the left image in the attached jpg.)

Compare this view with the SOHO/NASA spacecraft image taken 
approximately four hours earlier in visible light at a wavelength of 
about 680 nm (right image). This is similar to the transmission of 
the solar filter used on the three-inch telescope.

Notice the small telescope image shows not only sunspots, which are 
cooler than their surroundings, but also the Sun's limb (edge) 
darkening. In addition, several white light faculae are visible near 
the left and right edges of the Sun. These are brighter and hotter 
areas of the Sun's visible disk (photosphere) and best seen near the 
solar limb against the darker background of the limb darkening.

So, small scopes are not just for kids.

Photo Details: Unguided photo taken through a full aperture Thousand 
Oaks Type 2+ Glass Solar Filter (transmission 1/1,000 of 1%) using a 
Tele Vue 76 mm aperture, f/6.3 APO refractor telescope with a 480 mm 
focal length and equipped with a Tele Vue 4x Powermate Amplifier for 
an effective focal length of 1,920 mm. Camera Used: Canon EOS 5D Mark 
II; Exposure 1/250 at ISO 800; effective f-stop f/25; White Balance 
Auto. This is a single image photograph taken 2011 Nov. 10 at 18:26 
UT with some minor processing using Canon ZoomBrowser EX.

-----------------------------------------------------------------------------
THIS MESSAGE IS FROM THE AMATEUR TELESCOPE MAKERS & OBSERVERS
OF THE ALACHUA ASTRONOMY CLUB, INC. MAILING LIST
AAC Home Page:  http://www.floridastars.org
ATM-OBSERVERS-L Meetings Page: http://www.floridastars.org/atm/
ATM-OBSERVERS-L Archives: http://www.lists.ufl.edu/archives/atm-observers-l.html
ATM-OBSERVERS-L Subscription Info: http://www.floridastars.org/listserv/atml.html

POSTING MESSAGES TO THE ENTIRE ATM-OBSERVERS-L LIST:

1. Send your message to [log in to unmask]
2. Message will be distributed subject to approval by the sender
3. Please keep messages pertinent to the purpose of this list

TO UNSUBSCRIBE FROM THIS LIST:
1. Send e-mail to [log in to unmask]
2. In body of e-mail put UNSUBSCRIBE ATM-OBSERVERS-L
   (You must be logged on under same userid as when you originally subscribed.)

Top of Message | Previous Page | Permalink

Advanced Options


Options

Log In

Log In

Get Password

Get Password


Search Archives

Search Archives


Subscribe or Unsubscribe

Subscribe or Unsubscribe


Archives

March 2015
April 2014
March 2014
February 2014
January 2014
December 2013
November 2013
October 2013
July 2013
May 2013
April 2013
March 2013
February 2013
January 2013
December 2012
November 2012
October 2012
September 2012
August 2012
July 2012
June 2012
May 2012
April 2012
March 2012
February 2012
January 2012
December 2011
November 2011
October 2011
September 2011
August 2011
July 2011
June 2011
May 2011
April 2011
March 2011
February 2011
January 2011
December 2010
November 2010
October 2010
September 2010
August 2010
July 2010
June 2010
May 2010
April 2010
March 2010
February 2010
January 2010
December 2009
November 2009
October 2009
September 2009
August 2009
July 2009
June 2009
May 2009
April 2009
March 2009
February 2009
January 2009
December 2008
November 2008
October 2008
September 2008
August 2008
July 2008
June 2008
May 2008
April 2008
March 2008
February 2008
January 2008
December 2007
November 2007
October 2007
September 2007
August 2007
July 2007
June 2007
May 2007
April 2007
March 2007
February 2007
January 2007
December 2006
November 2006
October 2006
September 2006
August 2006

ATOM RSS1 RSS2



LISTS.UFL.EDU

CataList Email List Search Powered by the LISTSERV Email List Manager