MAY 2013

Volume XIII, No. 5

 This Month's coming events:

May 24 -- General Meeting, Kingwood College

June 7 -- Insperity Observatory Public Night

June 8 -- Star Party and BBQ, O'Brien Dark Site

Please see below for more information.

May 24, 2013

Novice Program

 6:30 - 7:15pm in the Cosmic Forum, upstairs in the CLA building

Dr. Aaron Clevenson


Main Presentation

Beginning at 7:30pm in the building CLA Teaching Theater

Author and NHAC member Allan Hall

"An Introduction to Long Exposure Astrophotography"

What’s Up Doc?” by Aaron Clevenson



1. NHAC members are now eligible for a discount on purchases at Land, Sea & Sky. Be sure to make your NHAC membership known when making a purchase.


2. The Comet Report is now available online.


3.  Ken Dwight has provided us an article giving information on cleaning a telescope mirror.  This sounds like one of those chores which has to be addressed from time to time.  I am keeping this Notice on the Newsletter for a while because it is full of good information on cleaning the mirrors.


4.  Name Badges:  We have name badges for many of our members (thanks, Aaron!). Please pick up your name badge when you arrive and wear it during the meeting. We would like for all our members to get to know each other.  Please don't forget to return the badge after the meeting.


5. We would like to welcome several New Members to the Club:  Ed Friani

          Kevin Milazzo

          Joseph Wagner

          Benjamin Feltner

          Lindsay Harmon

          George Roffe

          Desiree Carmona and family

          Sean McAntosh

          Paul MeLaughlin

We are glad you have chosen to join us.  Please do come to the Novice and General Meetings, and come out to the Dark Site as well.  We are definitely an observing club.  Our next Star Party and BBQ is June 8.  Please see below.  We look forward to seeing you.   

Star Party and BBQ, June 8, 2013


The Board of Directors has decided the focus of the Star Parties will be to give as much assistance as possible to new observers.  The BBQ itself will have the grill food starting at 6PM, giving time for eating, socializing, and setup before sundown at about 8:15 PM.

For the Star Party itself, the plan continues to be for a number of the more experienced observers to attend each of the Star Parties, with telescopes, so we "novices" will know there is someone who is planning to be at the Star Party with equipment and the desire to share knowledge.

For those who may not have been to the O'Brien Dark Site, it is just north of Dobbin on Highway 105 west of Montgomery.  It has reasonably dark skies, and a great low horizon in all directions.  The Owners, Tim and Wanda O'Brien are very cooperative hosts, and they do turn off any outside lights which might bother us.

The Dark Site address is: 27899 Myers Rd.
Montgomery, TX

On our NHAC web site, click on "Star Party!"  Scroll down to the O'Brien Dark Site information and look for the "detailed directions" link.  There are maps as well as directions.  There is also more information at the bottom of this Newsletter.  It is well worth the drive, which is about 10 minutes after you leave Dobbin going north.

Aaron Clevenson, James Billings, and likely Bruce Pollard are planning to be there to offer assistance to any who wish it.  I (Rusty) will be there, but the others named know a lot more than I.

Star Parties are scheduled for the Saturday on or just before the New Moon throughout the year.  This is to provide the best opportunity for dark skies.

Inclement weather, of course, can force Star Party cancellation or postponement. 


The Membership Committee will task itself with operating an occasional “door prize drawing” of astronomically related books, gadgets, accessories, or other items donated by members.  If you have stuff that it is time to pass on to astronomy-interested people, this is your opportunity.

See Stuart Davenport or myself if you have something to donate.
......George Marsden


Upcoming NHAC Meeting Schedule

 May 24 and June 28

NHAC is a proud member of:

2013 Public Nights*

June 7,          8:15 PM

July 5,           8:30 PM

August 2

September 6

October 4

November 1

December 6

These Public Nights are a tremendous opportunity for us to be a part of Astronomy Outreach, and also to observe with scopes we might never see, otherwise.  The Observatory has a 16" and a 20" telescope, each computer controlled, which provide awesome views of the sky.  There are typically 30 or 40 guests at the Public Night, several repeating, who are very appreciative of the opportunity to expose their kids to Astromony, and who enjoy the observing in their own experience, as well.  And then after all our guests have departed, several of us usually stay for a while and enjoy the views.  I (Rusty) have seen more detail on Jupiter from the Insperity Observatory than at any other time or place.

The Observatory is about 3/4 of a mile south of Will Clayton Parkway on S. Houston Ave, just north of Rankin Road in Humble.

For information, see the web site.


*Dates and times are subject to change.

The Insperity Observatory at Humble ISD, 2505 S. Houston Ave., Humble, TX 77396 281-641-STAR

Rusty's Ramblings...

Hi Folks:

I would like to share a technique for using an equatorial mount to locate objects without using the setting circles, and of course without using any go-to feature.  I only stumbled across this in the last couple of months or so.  I am sure it is a known technique and has been described before, but it was a revelation to me when I figured it out.  I have been using it to navigate the Virgo Cluster and others of my remaining Messier objects. No doubt there will be refinements I have not yet stumbled across. 

In essence, you locate an object of known declination near the object you are seeking, and "field hop" a given number of degrees east or west, and north or south.  In 2 parts, this month and next month, I will go into the various steps in this technique. 

For this month: 

1.  You must know where in the sky your target is.  It will be in some constellation, and you must take the time to learn what easily identifiable object is nearby-- perhaps in that constellation or the adjacent constellation.  This is homework you need to do in preparation for your observing session.  You are also going to learn the sky well enough to be able to find this easily recognizable object with certainty.  This object would typically be a star which forms part of the constellation "stick figure".  This object will be your "anchor" from which you will navigate to your target.

You are also going to figure how many degrees East or West, and North or South of your easily recognizable object your target is.  To do this, you need to consult a decent sky atlas.  I personally like Sky and Telescope's pocket Atlas, but there are several just as good, or better.

2.  Other homework you need to do is to figure out how many actual degrees of sky you can see in your telescope's view.  Here is how:

Every eyepiece has a specific "Apparent Field of View."  One of my favorite eyepieces has a 68 degree (68d) apparent field of view.  It also has a 32mm  focal length.  The telescope I use has a 1000mm focal length.  With this information you can figure out exactly what the "True Field of View" is for this telescope, with this eyepiece.  First, you need the magnification of the eyepiece.  Divide the focal length of the telescope by the focal length of the eyepiece.  In this case, divide 1000 by 32.   The answer is 31.25X magnification.  Just use 31X--  it is close enough.  Second, divide the apparent field of view, 68d, by the magnification, 31.  68/31=2.2 degrees.  That is the true field of view for this eyepiece in this telescope.  Write down this number with the eyepiece size, 32mm, and tape it on the side of the telescope so you can refer to it while observing.  Also calculate the same number for your other eyepieces, and write it down for them.  You will not need to calculate it again, but you will be able to use it every time you observe.

3.  When you setup your equatorial mount telescope for your observing session, be as precise as you can in aligning the Right Ascension axis with the true North Pole near Polaris.  In my telescope I have a pretty decent alignment scope which I use to align the scope as soon as it is dark enough to find Polaris with certainty.  But before it gets dark, I have already "rough" aligned the  "North" on the mount with the direction of North  at the observing site, and I have also set the latitude scale on the mount at 30 degrees, which is "close enough" for rough setting before it gets dark.  This has the effect of pointing the Right Ascension axis 30 degrees above the North horizon, which means it is pointed "pretty close" to the North Pole.  But after that I do need to wait until dark to get the final alignment, using the alignment instructions which came with the scope..

Next month I will go into how to use this homework and careful setup to actually find the target objects in the sky.  In the meantime, feel free to ask me or the other more experienced observers any questions you have.

Until next month, Clear Skies!


The North Houston Astronomy Club (NHAC), was formed for educational and scientific purposes, for people of all races, creeds, ethnic backgrounds and sex, for the primary purpose of developing and implementing programs designed to increase the awareness and knowledge of astronomy, especially for those living near the north side of Houston Texas.
NHAC is a not-for-profit organization dedicated to providing the opportunity for all individuals to pursue the science of astronomy, by observing in a dark-sky site, learning the latest technology, and sharing their knowledge and experience. Thus, our “Observe-Learn-Share” motto.

North Houston Astronomy Club is Sponsored by:


  • Membership Benefits
  • Discounts on purchases at Land, Sea & Sky. Be sure to make your NHAC membership known when making a purchase.
  • Loaner telescopes
  • Observe from Dark Sky Observing Sites
  • Learn from experienced amateur astronomers
  • Share your knowledge at club hosted picnics and star parties
  • Discount magazine subscriptions (contact our Treasurer)
  • Includes membership in the Astronomical League
  • The quarterly Astronomical League magazine “Reflector”
  • Borrow from the NHAC “Library”
  • Eligibility for NHAC Executive Board

Observe - Learn - Share

The North Houston Astronomy Club is a not-for-profit organization sponsored by Lone Star College-Kingwood, dedicated to increasing the awareness and knowledge of the science of astronomy. Public meetings are held each month on the fourth Friday.