Color Filters for the Planets

May 11th, 2012

This PDF file contains the tables and notes used the PowerPoint program that was given at the regular club meeting this year. The first section list each planet and the filters best suited to improve or enhance various visual planetary features. A narative description of the visual performance is present by Wratten filter number and color type desciption. 

A table format is next, listing each Planet, planet feature and filter most suited to enhance the visual viewing of the feature. This is good to use at the scope since it fits on on 8 x 10 sheet of paper.

The last section list the Wratten number, the planet it is to be used on and the feature on the planet the filter will enhance. This is the most common method that suppliers and dealers display their filters.

Download the pdf file Useful Filters for Planets


Here are Internet web sites that provide more information Color Filter for the planets.

The Abbey Road Observatory –

Observing the Planets with Color Filters –

Meade Filters –

The Meade 4000 Series –

Celestron –

Celestron Kits –


These three include Solar and DeepSky Filter, which I did not cover in te PowerPoint slide show.

The Use of Filters –

Optical Filter Guide –

Nebula Filter comparison on Deep Sky Objects –

Transit of Venus 2012

April 22nd, 2012
 Looking at the LAS 2012 calendar the club published and sold this year, you may have notice two line items for June 5, 2012. The first is the regular monthly meeting of the LAS, followed by the Transit of Venus. I compliment the club founders on their foresight on choosing the first Tuesday of each month in order for this rare event to fall on the same day. That’s advance planning at its finest.
 The viewing time circumstance of this transit is opposite of the June 8, 2004 event that was seen by the club members during sunrise. A hardy group gather before sunrise, ready their scopes and filters to witness the planet Venus against the solar background as the Sun rose on that summer morning. They were not disappointed for their efforts, with the added bonus of seeing Venus without the use of filters as the Sun rose in a low fog bank. We watched the end of the transit as Venus exit from in front of the solar surface.
 In 2012 the Transit of Venus be visible in our location during the late afternoon into early evening hours. Approximately 2.5 hours before sunset Venus will begin transiting the Sun, appearing on the solar limb at 6:03 pm EDT. The altitude of the Sun at that time is 25.7 degrees from the western horizon.

More information about the Venus Transit and safe viewing of the transit can be found on these web sites.
 Information about the Transit of Venus will be the topic of the regular meeting on May 1, 2012. Those bring scopes to view or photograph the transit should park in the field near the LAS roll off observatory. The time that the gate will open will be anounce at the meeting and in the future e-mail to club members.



Viewing Comet C/2009 P1 Gerradd

August 6th, 2011
The next few months comet C/2009 P1 Gerradd will be bright enough to be viewed with small scope. Its peak brightness may just reach 6th magnitude. Don’t expect a naked eye object, as the comet brightness is spread over 5 minutes or arc nebulous coma and a 6th magnitude star is a point source. Even a 6th magnitude star is difficult to see for many observers. This will be the brightest comet to be seen in some time. The visual magnitude is running a bit higher that the predicted magnitude estimates, but not by much. There is a little hope it may become brighter, not Comet Holmes brighter, rather a nice object to be seen with a telescope or larger binoculars.
Comet C/2009 P1 Gerradd is not a sungrazer, and will not produce a tail the likes of Hyakutake or Hale-Bopp, it closes approach to the sun is 1.25 AU on December 23, 2011. It is inclined 106 degrees the ecliptic and will be in view for a few months and will make its closest distance of 1.27 AU to the Earth on March 5, 2012.
To locate this comet I have produced a nightly ephemeris for a few months using SkyTools 2 software. The magnitude in the list is fainter than the observed magnitude at this time.
Other sources online to locate this comet can be found at these sites.
This site has good chart maps produced each month.
Charts with stars magnitudes that can be used to estimate the comet brightness are on this site.
To follow the progress of the comet these sites list recent reported visual magnitude of comets in the sky.
My last view of C/2009 P1 Gerradd was from Promise Land State Park on July 31, 2011 EDT. With my TV101 I could see the coma with easy at 36X. I located without the use of charts by recalling the position it was a week ago and that it would be near by M15 by now. Scanning the region with the 8 x 50 finder I soon located this position of the comet. A much better view was had with the 12inch reflector of Nancy and Ray Krake. The brighter inner and ghostly outer coma were move evident in the eyepiece view. It was still low in the eastern sky around 10:00 EDT, not a sign of a bright tail could be seen.


Saturn’s New Feature -The Serpent Storm

December 25th, 2010

As a response to all the attention that Jupiter has been receiving in the news, the planet Saturn is now putting on a show of a major storm in the North Temperate Zone.  Numerous amateur astronomers have been recording the development of this major outbreak.

As a long time observer of Saturn, a white spot this large and bright is a very rare event.  Visible features on the globe are usually small and dim, if visible at all.  Most are only discovered in photographs.  It is well worth your effort to see this current storm, even if you must content with winter conditions and rise up early to observe Saturn in the morning .

The following  are times when this ever expanding storm can be viewed in the Eastern Time Zone. How long this will be visible is not certain.

The white hue storm has spread out in the NTrZ and diminish in brightness. I am using the central Merdian of the major outbreak, more of the storm following it. It has been given a unoffical name as The Serpent Storm by those who view and image it frequently in the Saturn Yahoo Group.

As of June 2011 the Storm in the northern hemisphere of Saturn continues to show up in amateur photos.  Spreading across nearly the entire longitude there are few places it does not show up. This is a recent photo from TGC Observatory. Althought it was not seen visualy with the RC20 at any magnification. I could see the white belt  on the laptop screen using a  DFK31AUS camera for imaging.

Update CM  to 63.6 degrees SYSTEM III,  the Head of the Storm,  which is the latest information fron images by Efrain Morales Rivera posted on Saturn Yahoo Group on  June 17, 2011 .

Saturn North Equatorial Disturbance at  (NED) CM III 63.6   Eastern Daylight  Date and Time

6/18/2011 9:18:36 AM 7:58:02 PM 
6/19/2011 6:37:29 AM 5:16:55 PM 
6/20/2011 3:56:22 AM 2:35:48 PM 
6/21/2011 1:15:15 AM 11:54:41 AM 10:34:07 PM
6/22/2011 9:13:34 AM 7:53:01 PM 
6/23/2011 6:32:28 AM 5:11:54 PM 
6/24/2011 3:51:21 AM 2:30:48 PM 
6/25/2011 1:10:14 AM 11:49:41 AM 10:29:08 PM
6/26/2011 9:08:35 AM 7:48:02 PM 
6/27/2011 6:27:29 AM 5:06:56 PM 
6/28/2011 3:46:23 AM 2:25:50 PM 
6/29/2011 1:05:17 AM 11:44:44 AM 10:24:11 PM
6/30/2011 9:03:39 AM 7:43:06 PM 
7/1/2011 6:22:33 AM 5:02:01 PM 
7/2/2011 3:41:28 AM 2:20:55 PM 
7/3/2011 1:00:22 AM 11:39:50 AM 

John D Sabia