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JUNE 2018

UPCOMING EVENTS

Wednesday, June 6 - Regular PAC meeting @ 6:30 PM in the Davis Learning Center, Embry-Riddle Aeronautical University. There will be two speakers:

Joel Cohen (club member) will describe the April visit to the Mt. Lemmon Observatory (32 inch Schulman Telescope) as well as showing photos from the Biosphere, San Xavier Mission and Stellar Vision.

Ray Fobes (club member and volunteer adjunct with the Physics and Astronomy Department at ERAU) will present on “the Lunar Reconnaissance Orbiter”. Flying between 10 and 100 miles above the lunar surface the LRO is performing high-resolution mapping of the moon in up to ½ meter per pixel detail in addition to a host of other scientific measurements. Its ability to take 3D images adds to the overall understanding of the surface topology. This talk will be a brief walk through some of the more interesting images, including some in 3D. 3D glasses will be provided.

Saturday, June 9 to Saturday June 16 - Annual Grand Canyon Star Party, South and North Rims, Grand Canyon National Park.

Wednesday, June 13 - METASIG @ 5:00 PM at local restaurant. Sign up at June 6 meeting.

Wednesday, June 20 - Board meeting @ 6:00 PM in the Elsea Conference Room at the Prescott Public Library.

Saturday, June 23 - Starry Nights @ 5:30 - 10:30 PM in Pronghorn Park, Prescott Valley. This public viewing event is both solar and stellar. Sign up at June 6 meeting.

2018 SCITECH FEST

On Saturday, April 21 the Prescott Astronomy Club contributed to the annual SciTech Fest held at the event center at Embry-Riddle Aeronautical University. Participating members included

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Kathy and Dennis Eaton, Marilyn Unruh, John Carter, Ray Fobes, John Baesemann, Dwight Willman, Mike Vroom, Jack Szelka, David Viscio and Jerry Shaw. The club had a booth inside and solar viewing scopes outside.

2018 BUDGET & PAC PICNIC FUNDING APPROVAL

Both the PAC 2018 budget and a $500 funding request for the 2018 member picnic (to be held in September) was approved by club members at the May 2 general club meeting.

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LET’S TALK ABOUT THE MOON By John Carter, Sr.

Calling all members! Let’s have an open discussion on the Moon. The discussion can include:

1) Pictures with a DSLR and a tripod, single shot 2) Observing on vacation

3) Sharing the Moon with others

4) Get your birding binoculars out

5) Wherever the discussion goes

We’ll be asking for contributions during the short topic session at each meeting for the next few months. If you have pictures, bring them on a thumb drive to display on the big screen. For just talking about your experiences, the hand held mic will be passed around.

FOR SALE TO CLUB MEMBERS - CELESTRON NEXSTAR 8-INCH SCT

The Prescott Astronomy Club is offering for sale a Celestron telescope. Members who wish to buy it will have until May 31 to submit a sealed bid to John Baesemann (7295 N. Viewscape Drive, Prescott Valley, 86315). When the bid period has ended, bids will be opened and the member submitting the highest bid will be able to purchase the scope for his/her bid price. If there are no successful bids the item will be offered to the public at a higher price. The following is a description of the scope and accessories.

Celestron Nexstar 8-inch aperture, f/10, Schmidt-Cassegrain catadioptric. This is the original Nexstar, which doesn’t have some of the features of later models. It is a go-to scope with tracking.

Optical tube and mount weigh 24 lbs.

Celestron tripod, red dot finder, and hand controller

Power required –12 volts; has Delta Electronics AC to 12-volt, 3 Amp converter

Celestron diagonal -- 1 1/4"

Eyepieces: all 1 1/4" in a padded Orion case

Celestron 40mm Plossl, Meade 26mm Super Plossl, University Optics 32mm Koning

Barlow – 2X Celestron

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Filters 1 ¼-inch: Celestron LPR, Meade #58, 80A, 23A

Original Celestron manual and The NexStar User’s Guide, by Michael Swanson

The minimum bid price to members is $350. Anyone who is interested in seeing the telescope can contact Patrick Birck (pbirck@cableone.net) to arrange a mutually convenient time.

WHAT IS THE ASTEROID BELT? By Linda Hermans-Killiam

There are millions of pieces of rocky material left over from the formation of our solar system. These rocky chunks are called asteroids, and they can be found orbiting our Sun. Most asteroids are found between the orbits of Mars and Jupiter. They orbit the Sun in a doughnut-shaped region of space called the asteroid belt.

Asteroids come in many different sizes—from tiny rocks to giant boulders. Some can even be hundreds of miles across! Asteroids are mostly rocky, but some also have metals inside, such as iron and nickel. Almost all asteroids have irregular shapes. However, very large asteroids can have a rounder shape.

The asteroid belt is about as wide as the distance between Earth and the Sun. It’s a big space, so the objects in the asteroid belt aren’t very close together. That means there is plenty of room for spacecraft to safely pass through the belt. In fact, NASA has already sent several spacecraft through the asteroid belt!

The total mass of objects in the asteroid belt is only about 4 percent the mass of our Moon. Half of this mass is from the four largest objects in the belt. These objects are named Ceres, Vesta, Pallas and Hygiea.

The dwarf planet Ceres is the largest object in the asteroid belt. However, Ceres is still pretty small. It is only about 587 miles across—only a quarter the diameter of Earth’s moon. In 2015, NASA's Dawn mission mapped the surface of Ceres. From Dawn, we learned that the outermost layer of Ceres—called the crust—is made up of a mixture of rock and ice.

The Dawn spacecraft also visited the asteroid Vesta. Vesta is the second largest object in the asteroid belt. It is 329 miles across, and it is the brightest asteroid in the sky. Vesta is covered with light and dark patches, and lava once flowed on its surface.

The asteroid belt is filled with objects from the dawn of our solar system. Asteroids represent the building blocks of planets and moons, and studying them helps us learn about the early solar

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system.

For more information about asteroids, visit: https://spaceplace.nasa.gov/asteroid

This image captured by the Dawn spacecraft is an enhanced color view of Ceres, the largest object in the asteroid belt.

Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

LET'S PARTY FOR JUNE Astronomical objects for public (and private) star parties. by Fulton Wright, Jr.

Flashy, deep-sky objects, visible in the middle of the month, at the end of astronomical twilight, 8:00 PM in March, (when it really gets dark). This list customized for Prescott, Arizona, should work well anywhere in the state, and be usable anywhere in the old 48 states.

Double Stars (2 or 3 stars, close together)

Beta Cygni (Albireo, SAO 87301) Mag: 3.4 (yellow) & 4.7 (blue), Sep: 35 arc-sec R.A.: 19hr 31min, Dec.: +27deg 58'

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Zeta Ursae Majoris (Mizar, SAO 28738) Mag: 2.2 & 3.9, Sep: 14 arc-sec R.A.: 13hr 24min, Dec.: +54deg 56' Epsilon Lyrae (Double-Double, SAO 67310 & 67315) Mag: 5.0 & 6.1, 5.3 & 5.4, Sep: 2 arc-sec, 2.5 arc-sec R.A.: 18hr 44min, Dec.: +39deg 40' Gamma Leonis (Algiba, SAO 81298) Mag: 2.2 & 3.6, Sep: 5 arc-sec R.A.: 10hr 20min, Dec.: +19deg 51'

Open Clusters (about 50 bright stars)

Collinder 399 (Coat-hanger) Mag: 3.6, Size: 90 arc-min R.A.: 19hr 25min, Dec.: +20deg 11' IC 4665 Mag: 4.2, Size: 70 arc-min R.A.: 17hr 46min, Dec.: +05deg 43' NGC 6633 (use wide field) Mag: 4.6, Size: 30 arc-min R.A.: 18hr 27min, Dec.: +06deg 30'

Globular Clusters (about 200,000 dim stars) (this is not a good season for globulars.)

M 5 (NGC 5904) Mag: 5.6, Size: 3.5 arc-min R.A.: 15hr 19min, Dec.: +02deg 05' M 4 (NGC 6121) Mag: 5.6, Size: 8.7 arc-min R.A.: 16hr 24min, Dec.: -26deg 32' M 13 (Hercules Cluster, NGC 6205) Mag: 5.8, Size: 20 arc-min R.A.: 16hrs 42min, Dec.: +36deg 28'

Galaxies (about 200,000,000 very dim and distant stars)

M 82 and M 81 (Bode's nebula, NGC 3031 and NGC 3034) Mag: 6.8 and 8.1, Size: 21 x 11, 11 x 5 arc-min, 37 arc-min apart R.A.: 9hrs 55min, Dec.: +69deg 55'

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M 104 (Sombrero Galaxy, NGC 4594) Mag: 8.2, Size: 8 arc-minutes R.A.: 12hrs 40min, Dec.: -11deg 37'

M 51 (Whirlpool Galaxy, NGC 5194, low but rising) Mag: 8.0, Size: 14 x 12 arc-min R.A.: 13hrs 30min, Dec.: +47deg 12' M 83 (NGC 5236) Mag: 7.5, Size: 13x12 arc-min R.A.: 13hr37min, Dec.: -29deg 52'

Diffuse Nebulae (Gas and dust lit by a nearby star. This is not the season for nebulae.)

none available Planetary Nebulae (gas shell from exploding star, looks like Uranus in telescope)

M 57 (NGC 6720, Ring Nebula) Mag: 8.8, Size 1.4 x 1.1 arc-min R.A.: 18hr 54min, Dec.: +33deg 02' NGC 6826 (Caldwell 15, Blinking Planetary Nebula) Mag: 8.9, Size: 2.1 arc-min R.A.: 19hr 45min, Dec.: +50deg 31' NGC 6543 (Cat's Eye Nebula, Caldwell 6) Mag: 8.1, Size: 0.4 arc-min R.A.: 17hrs 59min, Dec.: +66deg 38'

For additional information, see: www.dso-browser.com

NEED TO KNOW - ASK A MEMBER

A new 15-minute segment is being added to the regular general meetings where members can have their ‘burning’ questions answered by other knowledgeable members. If you have an astronomy related question you would like explained, submit the question to Jeff Stillman (jstillman50@cableone.net). You can also bring up the question at the meeting.

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BOOKS AND MAGAZINES

Over the years astronomy books have been donated to PAC. Boxes of these books will be available at the regular meetings. For a donation to PAC of $1 per book, anyone can have a book. Books that are not purchased at a regular meeting will be available at the following Third Thursday programs. Any remaining unsold books will be donated to the Friends of the Prescott Public Library. We also have copies of past Sky and Telescope magazine. These will be available to any member wishing to take them. Unclaimed magazines will be recycled.

FOR SALE

Please visit the Classified Ads section of the club website to view the items posted there for sale:

http://prescottastronomyclub.org/classified-ads/

New items are added now and then, so don’t miss out on something that you would like to get for yourself...or a friend.

PAC MENTORS

If you need advice on the purchase of astronomy equipment, setting up equipment, astrophotography, etc., contact a PAC mentor.

Jeff Stillman - Astrophotography - (928) 379-7088

David Viscio - General - (928) 775-2918

Greg Lutes - Visual Observing - (928) 445-4430

Joel Cohen - Beginner’s Astronomy: Selecting & Using a Telescope - (856) 889-6496

Bill McDonald - Video Observing

John Carter - Video Observing - (928) 458-0570

OBSERVING LISTS

Observing lists are available in PDF format on the PAC website to provide guidance and goals for visual and astrophotography programs.

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Astroleague Lunar 100 Binocular Showpieces

Bright Nebulae Caldwell

Dunlop 100 Face-On Spiral Galaxies

Globular Clusters Herschel 400

Herschel II Hidden Treasures

Messier Open Clusters

Planet Maps Planetary Nebulae

Royal Astronomical Society of Canada Finest NGC

Saguaro Astronomy Club Best NGC S&T Lunar 100

Telescope Showpieces The Secret Deep

PAC WEBSITE & YAHOO GROUPS

Website: http://www.prescottastronomyclub.org

E-mail: pacinfo@prescottastronomyclub.org

Astrophotography special interest group:

https://groups.yahoo.com/neo/groups/pacastrophotography/info

BOARD OF DIRECTORS President: Jeff Stillman At Large: Pat Bledsoe Vice President: John Carter At Large: Dennis Eaton Secretary: Doug Tilley At Large: Adam England Treasurer: John Baesemann At Large: Joel Cohen

PAC COORDINATORS Astronomical League Coordinator: Pat Birck Facebook: Adam England Highland Center Coordinator: David Viscio

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Hospitality: Cory Shaw Magazine Subscriptions: John Baesemann Membership: John Baesemann METASIG: Marilyn Unruh Newsletter: David Viscio PAC Affiliate Partner w/ NAU Space Grant Program – Jerry & Cory Shaw PAC Store Sales: John & Laura Verderame Refreshments: Liz Dano Property Records: Doug Tilley Publicity: Adam England Schools & Camps Outreach: Pat Birck Starry Nights Coordinator: Pat Birck Third Thursday Coordinator: Cory Shaw & Pat Birck Webmaster: Russell Chappell

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ASTRONOMY PICTURE OF THE DAY: May 7, 2018

THE UNUSUAL BOULDER AT TYCHO'S PEAK

Main Image Credit: NASA, Arizona State U., LRO Upper Inset: NASA, Arizona State U., LRO

Lower Inset: Gregory H. Revera

Why is there a large boulder near the center of Tycho's peak? Tycho crater on the Moon is one of the easiest features to see, visible even to the unaided eye (inset, lower right). But at the center of Tycho (inset, upper left) is a something unusual -- a 120-meter boulder. This boulder was imaged at very high resolution at sunrise, over the past decade, by the Moon-circling Lunar Reconnaissance Orbiter (LRO). The leading origin hypothesis is that that the boulder was thrown during the tremendous collision that formed Tycho crater about 110 million years ago, and by chance came back down right near the center of the newly formed central mountain. Over the next billion years meteor impacts and moonquakes should slowly degrade Tycho's center, likely causing the central boulder to tumble 2000 meters down to the crater floor and disintegrate.