November 2024 Meeting Notes

Bartlesville Astronomical Society Meeting Notes

November 4, 2024

Attendance:  We had 19 in attendance this evening, 4 guests (our guest speaker, John Land and his wife, and two other guests who joined our Club this evening) and 15 members, in person and on Zoom.  

John Grismore, at his first meeting presiding as President since he was elected in October, expressed thanks to Craig for being President during the pandemic; to John B for being President last year; to Evan for being Treasurer for the past few years; and to Denise for being a Secretary-plus.  He also thanked Luann for volunteering to be Event Coordinator and to Mike Woods for continuing to write our newsletter.  He also thanked Pat for being our new Vice President.

During the meeting, Evan volunteered to be the “technical person” at Club meetings (i.e. handle Zoom) and Pat S. volunteered to be his backup.

We signed a card for Fred Frey that Denise got, to thank him for donating telescopes and books to our Club.

Astronomical trivia—John G:

1 year is 365.24219 days. 

The Earth is about 93 million miles from the Sun.  At perhelion, it is 91,404,095 miles; at aphelion, 94,510,528 miles.  The average distance is 92,955,807 miles.

There are eight planets orbiting the Sun, although the state of New Mexico still recognizes nine planets.

Astronomy basics—Brian T:

Astronomy 101, Classification of Galaxies

William Parsons was the first person to sketch the structure of a galaxy.

Edwin Hubble was the first to confirm the existence of a galaxy beyond our own.

Half of all galaxies are elliptical galaxies.

Spiral galaxies are rich in gases and involved in active star formation.

Barred spiral galaxies, such as ours, have spiral arms attached to a central bar.

Irregular galaxies are galaxies that don’t have a distinct shape.

Brian showed images of the different types of galaxies.

Recent Club Events:

October 10 - Dewey Boys and Girls Club “Lights on After School”:  BAS members set up a table with handouts, lots of astronomy pictures and two telescopes.   The event took place from 4:30-6:30 p.m. and volunteers gathered at 3:30 p.m. to do setup.

John B organized this event on behalf of the Club.  We looked at the Sun (with solar filters) and the Moon.

Second-Saturday-of-the month star party on October 12:  The main focus of this star party was Comet C/2023 A3 (Tsuchinshan-ATLAS).  We intended to meet at Sooner Park, which had better visibility to the west than Jo Allyn Lowe Park, but relocated to a parking lot near Hoover Elementary because of BooFest.  We looked for Comet Tsuchinshan early in the evening.  We were hampered by lights and partly cloudy skies, but eventually found the comet. Clouds continued to gather, preventing additional observing, but many stayed around to visit!

Upcoming Club Events:

November 9 - Public Star Party at Jo Allyn Lowe. Setup at sunset.

November 19 - Cub Scouts learning astronomy at Good Shepherd Presbyterian Church.  Need volunteers and telescopes.  We decided to do this event on November 19 (the other option was  November 12).

November 23 - Dark Sky Observing at Girl Scout Camp?

December 2 - BAS Meeting - “A Year’s Worth of Meteor Showers” by Denise G December 9 - Public stargazing at Jo Allyn Lowe, featuring Geminid meteor shower

January 6 - BAS Meeting - “New Telescope for Christmas? How Do You Use It?”

March 2025 - Library Display. We decided to have our first brainstorming session November 16.  We will be in case B on the other side of the room.  Ideas will be welcome for how to set this up! 

Treasurer’s Report – Evan Z:

Ending balance September 30, 2024:  $16,138.18.  (This is Arvest and Truity accounts combined.)

Additions:

Truity savings account interest: $49.16.

Dues: $65.00

Donations from Benevity/ConocoPhillips: $123.00

Expenses:

Pizza at the Bolinger's star party: $65.66.

Luann W. reimbursement for trivia prizes: $45.12.

John B reimbursement for thank-you cards: $10.86.

Ending balance October 31, 2024: $16,253.70.

Upcoming Astronomical Events:

Nov 15 - Full Moon / Beaver Moon

Nov 17/18 Leonid Meteor Shower

Dec 1 - New Moon

Dec 7 - Jupiter at Opposition, visible all night

Dec 14/15 - Geminid Meteors

Dec 15 - Full Moon / Cold Moon

Dec 21 - Winter Solstice

Dec 25 - Mercury at Greatest Elongation West, farthest from Sun in sky, visible before sunrise

Dec 30 - Black New Moon, second New Moon of the month

Full Planetary Alignment:

On Friday, February 28, 2025 there will be a full planetary alignment visible shortly after sunset. Seven planets will be visible in the sky at the same time. Saturn, Mercury and Neptune will be low in the west, with Venus a little higher. Uranus, Jupiter and Mars will be lined up near the ecliptic, high overhead arcing over Orion. And as a bonus, a very thin crescent Moon may (or may not) be visible halfway between Saturn and Mercury This might make a great special event for public view.

Requests:

Do you have astronomy pictures you’d like to share at a BAS meeting? Email them to bvilleastro@gmail.com.

BAS needs volunteers to help with the following:

Website maintenance

Public outreach

Meeting programs and Astronomy Basics segments

Equipment inventory and checkout system

Anything you can do to help

BAS Text Alerts:

We’re still working on a way to provide time critical alerts to members who opt-in to a future alert system. The methods we have tried so far have had significant drawbacks. We hope to try the GroupMe app in the near future.

For Sale:

1. Orange tube Celestron 8" SCT with 2-inch diagonal and Telrad finder- $450

2. Celestron 6" f/5 reflector with tube rings and rail and Telrad finder- $150

Contact Don Fudge at donfu61@gmail.com

Top Ten Tips for Buying a Telescope: https://www.cloudynights.com/articles/cat/astro-geartoday/more/beginners-guides/top-ten-tips-for-buying-a-telescope-r4643

Main presentation by John Land, “Beginning Your Journey of Discovery in the Night Sky” 

John has been a member of the Astronomy Club of Tulsa since 1977.  He began teaching a high school astronomy class in 1978.  In 2004 he received the Astronomical Society of the Pacific’s Thomas A. Brennan award for high school astronomy education!

John has held a number of leadership positions within the Astronomy Club of Tulsa.

John suggested these first steps for beginning your journey of discovery in the night sky:

·       Take time to let your eyes adapt to the dark sky—this takes at least 10 minutes. 

·       Use a dim red-light flashlight outside.

·       Learn brighter stars by name.

·       Then learn to trace constellations.  Where do you start with that?  Find a pattern that is easy for you to visualize.  You can use stick figures to help you!

·       The Stars by H.A. Rey is a helpful book. 

·       Find the Constellations, also by H.A. Rey, is a useful book for younger children.

·       There are useful apps you can use with your mobile phone or other mobile device.

Constellations vs. asterisms:

·       Constellations are official arrangements named for persons, animals or objects.  There are 85 official constellations.

·       Asterisms are simple patterns of stars with popular names.  The Teapot and the Summer Triangle are examples of asterisms.

Telescope basics:

·       The telescope objective is the part of a telescope that gathers and focuses light.

·       The aperture of a telescope describes the diameter of the objective.  You can also think of it is as the size of the telescope.

·       The focal length of a telescope is the distance from the objective to the point of focus.

·       The f/number is the ratio of the focal length to the aperture. 

·       A six-inch telescope has an aperture of six inches or 150 mm.  (50 mm is about two inches.)

There are three telescope performance criteria:

·       Light—the amount of light that is collected and brought to focus. 

o   The larger the aperture, the more light is grasped. 

o   The area of a telescope is defined as π times the radius of the telescope, squared. 

o   An 8-inch telescope will admit 4 times more light than a 4-inch telescope.

·       Resolution—the ability to see fine distances or closely-spaced stars.

o   1 arc second is 1/3600 of a degree.  The human eye can detect 60 arc seconds.

o   A 60 mm telescope’s resolution is 3.2 arc seconds—20 times better than naked eye.

o   A 150 mm telescope’s resolution is 0.8 arc seconds—75 times better than naked eye.

o   The larger the objective aperture, the better the resolution capability.

o   Note that visibility in our atmosphere often limits resolution to one arc second.

·       Magnification—the number of times an object appears larger or nearer.

o   A 60 mm scope will give 120 times magnification.

o   A 180 mm scope will give 300 times magnification.

o   Note that visibility will often limit a telescope to 200 times magnification.

o   Magnification can be changed by selecting a different focal length eyepiece.

o   Magnification is scope focal length divided by eyepiece focal length

o   30-40 X magnification will give you a wide field view to locate objects.

o   80-100 X magnification will let you see the moon, planets, star clusters, nebulae, galaxies.

o   120-150 X magnification will let you see more specific details in planets; double stars; etc.

o   Avoid eyepieces with a focal length of less than 6 mm.   Instead, use a 2X Barlow lens.

Basic telescope designs:

·       Refractor—Uses lenses to gather and focus light. 

o   An achromatic refractor has two lenses and different shapes and glass types. 

o   An apochromatic refractor uses three lenses to correct for red, green and blue light.

o   An ED refractor uses an extra-low dispersion type of glass doesn’t disperse color like traditional achromatic glass objectives do.

·       Reflector—developed by Isaac Newton

o   Uses mirrors to gather and focus light.  Reflector telescopes use a parabolic primary mirror, and a flat, diagonal mirror redirects the light path for viewing.

o   Advantages: 

§  All light colors are reflected equally.

§  Only the front surface reflects light.

§  Light doesn’t pass through the glass.

§  The mirror weight is supported in the back of the telescope.

o   All of the world’s major telescopes are reflectors.

·       Catadioptric telescope

o   Uses both mirrors and lenses to direct light along a folded focal length. 

o   The telescope’s folded light path allows for a longer focal length in a shorter, more portable assembly.

o   The telescope mount is more compact and compatible with computer-controlled guidance systems. 

o   Downside—more expensive.

What scope is good to begin with?  The one you will use often!

Whatever type of telescope you start with,

·       Buy a good star atlas and a good phone app.

·       Choose one area of the sky to explore, to start.

·       Earn Astronomical League observing certificates and pins

A refractor telescope is a good beginner scope for youth. 

·       It has a sealed tube to keep dust out.

·       No optical path alignment is needed.

·       Easy to set up and use quickly.

·       No central obstruction in light path.

·       Can use an achromatic glass objective—70-100mm aperture.

·       A 1.25-inch eyepiece size is preferable; use two eyepieces.

·       Look for a well-made mount with sturdy tripod.

·       Get an alt-azimuth mount, not an equatorial one.

·       Buy from a reputable telescope dealer, not a big box store or a toy store.

·       Don’t be fooled by false magnification claims or Amazon best seller promotions!

Reflector telescopes offer larger aperture at a lower cost ratio.

Disadvantages:

·       Shorter f/ratios, f/8 to f/5

·       Tube open to air—keep covered to prevent dust.

·       Mirror alignment needs occasional adjustments.

·       Diagonal mirror blocks some light.

·       Diagonal vanes produce diffraction spikes.

Example of a price point:  Dobsonian 8-inch aperture f/5.9 reflecting telescope with an 9 mm 1.25 inch Plossl eyepiece, telescope tube length 46 inches (1200 mm), total weight 60 lb., costs about $600 plus add a Barlow lens for about $80.00.  Good visual scope, no star tracking, aim with finder and push to target.