star gazer newsdelmarvastargazers.org/newsletter/news2014/jul2014news.pdfjuly 2014 page 1 volume 21...

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July 2014 Volume 21 Number 01 Page 1 Star Gazer News Newsletter of the Delmarva Stargazers www.delmarvastargazers.org From the Prez… The Delmarva Stargazers are starting another year and amazingly it’s our 21 st ! Sum- mer is here and hopefully some clear nights for observing. We certainly saw some clear skies during the first week of June. With some luck, maybe the skies will be clear for us this summer. Some of the Stargazers are going to Cherry Springs Star Party in Pennsylvania at the end of the month. It will be nice to view in some dark skies. I have always enjoyed Spruce Knob in West Virginias with its dark skies. Be sure to attend one of our dark sky observing sessions this summer, even if, you don’t have a telescope or a binocular. Rou- tinely check for some announcements on our Ya- hoo group or Facebook. At the present time, your Stargazers officers are Lyle- President, Don Surles- Past -President, Kathy Sheldon- Treasurer, and Cal Estrada- Secretary. Unfortunately, we have no nominee for President-Elect. Don Surles stated that he would run for President-Elect, if no one else volunteers. We need members to come forward and become club officers! It is time for you to help the Stargazers. Some of the officers are getting tired and fresh views are needed to keep our club viable! Presently, we are talking to Trap Pond State Park in Laurel, DE about using an area of the park for observing. A 10 acre site within the Park would make a great observing area. The area is surrounded by trees, and is darker than our Tuckahoe and Blackbird observ- ing sites. As a Club, perhaps 10 years ago by now, we had an opportunity to observe there as part of Laurel School District’s middle school event for students with good school atten- dance, passing grades and who stayed out of the principal’s office. My initial discussions with Raymond Bivens, Delaware’s Director of Parks and Recreation, indicated that they want us! Director Raymond Bivens knows the Delmarva Stargazers because he was a Park Ranger at Tuckahoe State Park in Maryland and had worked with us previously. On June 18 th , we will meet with William Koth, the Nature Center Manager at Trap Pond State Park, to discuss using this area for observing and perhaps for our spring and fall star parties. We have already set up an observing session at the Park for the week- end of July 25 Th and 26 Th . The 26 th is the rain date. More details will be posted on our Yahoo group and on our Facebook page after the meet- ing with Mr. Koth. Regardless of the outcome of our meeting with Mr. Koth, our N0-FRILLS Star Party this fall will be at Tuckahoe State Park at the Equestrian Center! Earlier this year Don Surles asked the Club members attending one of our spring meet- ings what they wanted at the meetings. Many of the attendees want information on telescope making and perhaps assistance with building a scope. Others wan6 some Skype presentations; most wanted cookies! So starting in September, we will have presentations on various aspects of telescope making, 3 to 4 Skype presenta- tions and hopefully some other presentations discussing NASA’s projects. I will also try to have some presentations on current research at Del State, U of D and Wallops Island. Of course, we will have cookies!! During either our January or February meeting, Dan Kennedy will be doing a presentation on his Ponce’t mount which he has used for years. This type of mount allows a dobsonian scope to track an object for a short period of time. Don Surles also stated that he would assist anyone who is already building a scope and needs some assistance and, if he could not help, Don would find him someone else who would assist them. -Lyle Jones Upcoming Events: Meeting ! NO MEETING THIS MONTH Observing ! July 7-8 th Dusk Eq. Cntr & BB Picnic (see Pg.7) July 12th 1 PM Surles residence Observing ! July 25 th Dusk Trap Pond SP

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Page 1: Star Gazer Newsdelmarvastargazers.org/newsletter/news2014/jul2014news.pdfJuly 2014 Page 1 Volume 21 Number 01 Star Gazer News Newsletter of the Delmarva Stargazers From the Prez…

July 2014 Volume 21 Number 01 Page 1

Star Gazer News

Newsletter of the Delmarva Stargazers www.delmarvastargazers.org

From the Prez… The Delmarva Stargazers are starting

another year and amazingly it’s our 21st! Sum-

mer is here and hopefully some clear nights

for observing. We certainly saw some clear

skies during the first week of June. With some

luck, maybe the skies will be clear for us

this summer. Some of the Stargazers are going

to Cherry Springs Star Party in Pennsylvania

at the end of the month. It will be nice to

view in some dark skies. I have always enjoyed

Spruce Knob in West Virginias with its dark

skies. Be sure to attend one of our dark sky

observing sessions this summer, even if, you

don’t have a telescope or a binocular. Rou-

tinely check for some announcements on our Ya-

hoo group or Facebook.

At the present time, your Stargazers

officers are Lyle- President, Don Surles- Past

-President, Kathy Sheldon- Treasurer, and Cal

Estrada- Secretary. Unfortunately, we have no

nominee for President-Elect. Don Surles stated

that he would run for President-Elect, if no

one else volunteers. We need members to come

forward and become club officers! It is time

for you to help the Stargazers. Some of the

officers are getting tired and fresh views are

needed to keep our club viable!

Presently, we are talking to Trap Pond

State Park in Laurel, DE about using an area

of the park for observing. A 10 acre site

within the Park would make a great observing

area. The area is surrounded by trees, and is

darker than our Tuckahoe and Blackbird observ-

ing sites. As a Club, perhaps 10 years ago by

now, we had an opportunity to observe there as

part of Laurel School District’s middle school

event for students with good school atten-

dance, passing grades and who stayed out of

the principal’s office. My initial discussions

with Raymond Bivens, Delaware’s Director of

Parks and Recreation, indicated that they want

us! Director Raymond Bivens knows the Delmarva

Stargazers because he was a Park Ranger at

Tuckahoe State Park in Maryland and had worked

with us previously. On June 18th, we will meet

with William Koth, the Nature Center Manager

at Trap Pond State Park, to discuss using this

area for observing and perhaps for our spring

and fall star parties. We have already set up

an observing session at the Park for the week-

end of July 25Th and 26

Th. The 26

th is the rain

date. More details will be posted on our Yahoo

group and on our Facebook page after the meet-

ing with Mr. Koth. Regardless of the outcome

of our meeting with Mr. Koth, our N0-FRILLS

Star Party this fall will be at Tuckahoe State

Park at the Equestrian Center!

Earlier this year Don Surles asked the

Club members attending one of our spring meet-

ings what they wanted at the meetings. Many of

the attendees want information on telescope

making and perhaps assistance with building a

scope. Others wan6 some Skype presentations;

most wanted cookies! So starting in September,

we will have presentations on various aspects

of telescope making, 3 to 4 Skype presenta-

tions and hopefully some other presentations

discussing NASA’s projects. I will also try to

have some presentations on current research at

Del State, U of D and Wallops Island. Of

course, we will have cookies!! During either

our January or February meeting, Dan Kennedy

will be doing a presentation on his Ponce’t

mount which he has used for years. This type

of mount allows a dobsonian scope to track an

object for a short period of time.

Don Surles also stated that he would

assist anyone who is already building a scope

and needs some assistance and, if he could not

help, Don would find him someone else who

would assist them.

-Lyle Jones

Upcoming Events: Meeting ! NO MEETING THIS MONTH Observing ! July 7-8

th Dusk Eq. Cntr & BB

Picnic (see Pg.7) July 12th 1 PM Surles residence Observing ! July 25

th Dusk Trap Pond SP

Page 2: Star Gazer Newsdelmarvastargazers.org/newsletter/news2014/jul2014news.pdfJuly 2014 Page 1 Volume 21 Number 01 Star Gazer News Newsletter of the Delmarva Stargazers From the Prez…

July 2014 Volume 21 Number 01 Page 2

Choosing and Using a Refracting Telescope

Book Review

by Fred De Lucia

Owning, at present, three refractors

I find myself returning to this book every

once in a while to refresh my memory of

what I should be getting out my stable of

Galieo’s choice of instrument. I’ve owned 5

in the last 7 years, 6 if I count the Sears

vinyl clad cardboard one my parents gave me

when I was a pre-teen. My current three are

a 120mm f/7.5 ED doublet apo, 102mm doublet

f/9.8 achro and an 80mm triplet f/6 apo. I

enjoy them all immensely, using them with

surprisingly good effect on objects, both

celestial and terrestrial. Over the years I

sold a 152mm f/5.9 achromat and an 80mm f/7

aplanat for various reasons, only to move

on to something more practical or with bet-

ter optics. So, I offer this review not

just for those who are in the market for a

refractor and would like some education on

choices, but, also, in the spirit of shar-

ing, what I found as, an enjoyable read.

Choosing and Using a Refracting Tele-

scope by Neil English is from Springer’s

Patrick Moore’s Practical Astronomy Series

(2011, list $39.95). The book is laced

with a variety of photographs of refrac-

tors, both old and new, in an equal variety

of photographic quality. There’s more than

a nod to Suiter’s “Star-Testing Astronomi-

cal Telescopes”, too. English gives short

but quite informative instructions on how

to evaluate visually: coatings, astigma-

tism, coma, spherical aberration and field

curvature. By doing so in simple terms he

arms his audience with enough knowledge to

shop for a quality refractor with a fair

degree of confidence.

He dwells just long enough on optics

and its math to give the basics behind the

Fraunhofer, Clark, Cooke and Littrow de-

signs. He provides a very interesting over-

view of the history of the refractor tele-

scope, emphasizing how long focal length

refractors were used in the 18th century for

astute astronomical observations with in-

strumental focal ratios as long as F/50 and

focal lengths of 150 feet in some very suc-

cessful attempts to reduce false color. He

points out how such scopes were able to

discern details of Saturn’s rings and Mars’

rotational characteristics in the budding

years of astronomical research.

English educates his reader with an-

ecdotal references from telescope collec-

tors that can generate passion for seeking

out such instruments, or at least, travel-

ing to where they can be seen and possibly

gazed through. In the chapter “Going Retro”

he relates how a 9” Clark refractor that

was built in 1915 was literally given away

by a university in the 1970’s just before

loading it on a truck for disposal in a

dump.

Crown and flint, fluorite, Ohara,

Hoya, the ED doublet, triplet and 4-element

designs are all duly explained in under-

standable language, noting their strengths

and applications. Spending some time on the

color free, flat field Tele Vue Genesis 4”

F/5 four-element modified Petzval and other

milestones of design, English has a knack

for preparing the enthused beginner for

what many have already come to recognize as

a life changing journey.

Accessories are given due credit in-

cluding selecting eyepieces, mounts and use

of filters. The lens designs for binoculars

and sport optics are summarized, also,

along with some very practical advice for

daytime observing on choice of aperture and

optical design.

Readily admitting that the refractor

market is too broad and advancing too

quickly to address fully all makes and mod-

els, especially regarding the developing

shorter focal length larger aperture Apo

market, English wisely selects what he re-

views. Similarly, I am faced with the task

of mentioning only highlights of a book

that really encompasses more information

than that which a review can do justice.

The major players like APM, Astro-Physics,

Celestron, Orion, Pentax, Stellarvue, Tele

Vue, Vixen and others are represented, as

well as, lesser known names to the beginner

such as Bresser, Swift, or D&G and he gives

a respectful bow to Unitron for its

“beautiful, high specification” renowned

performing achromats. It’s obvious that he

has a particular affinity for the Russian

made 4” F/10 Tal 100R often referencing it

when reviewing other scopes. To expand the

scope (pun intended) of his reviewing, he

relies on actual user comments by seasoned

amateurs such as Pollux Chung, Karl Krasley

(co-founder of the ChesMont Astronomcial

Society in PA) or Clive Gibbons so as to

give the reader more than a one author

viewpoint. Bear in mind, also, that al-

though this book was published in 2011 it

still has significant value for today’s

market. His most detailed review is an 8

page report on a Skylight F/15 4” Fraunhof-

fer achromatic doublet, his personal favor-

ite…and a mouthwatering review it is. Sky-

light has since produced a very interesting

line of refractors with classic appeal.

While being a guide for refractor

telescopes, it also seems to attempt to

Page 3: Star Gazer Newsdelmarvastargazers.org/newsletter/news2014/jul2014news.pdfJuly 2014 Page 1 Volume 21 Number 01 Star Gazer News Newsletter of the Delmarva Stargazers From the Prez…

July 2014 Volume 21 Number 01 Page 3

Your 2012-2013 Officers Office Officer Phone email President Lyle Jones 302-736-9842 [email protected] President-elect Don Surles 302-653-9445 [email protected] Secretary Cal Estrada Treasurer Kathy Sheldon 302-422-4695 [email protected] Past President Don Surles 302-653-9445 [email protected]

bring the argument of Apo vs. Achro to a

logical conclusion. Although English gives

full credit to Apos for their lack of chro-

matic aberration and other Seidel aberra-

tions, he spares no opportunity to tout the

character of long focal length achromatic

refractors. The book almost reads like it’s

aimed at the enthusiasts who either rarely

or never go to a dark site. Although that

probably broadens his potential readers, I

don’t think it does full justice to the

hobby. He frequently uses the Double-

Double, Sirius, Venus and other bright

backyard objects when describing optical

performance. He never makes mention of ap-

plying an Achro to deep sky use. For exam-

ple, Achros perform competitively well

against their 5x-10x the price Apo cousins

when observing galaxies, galaxy clusters,

globulars, nebulae and even comets because

the visual magnitude of such objects is be-

low the threshold of any chromatic aberra-

tion of most doublets. Granted, one needs

to go “dark” for these targets but I would

be remiss to ignore the author’s oversight.

As with every book I’ve read in this

series, Springer’s proclivity for grammati-

cal errors and just plain missing words is

evident, although much less so than in oth-

ers in their collection. The read can be

quick, or one can dwell on specifics where

unfamiliarity is encountered. It’s both an

informational review of many refractor

telescopes as well as a casual walk through

many readers’ chosen avocation. Recom-

mended.

Making your own newtonian

primary mirror cell…

By Don Surles

First...why would you want to make your own

mirror cell?

Answer:

They are less expensive

You can make one to fit your tube’s ex-

act inside diameter

You may not find a mirror cell on the

market

You can arrange the support system to

suit your mirror

Here is an example

of one I made for a

12.5” mirror.

The list of materials is:

3 ea 1/4 -20 X 1.5” machine bolts

3 ea 1/4 -20 X 2” machine bolts

9 ea 1/4” flat washers

7 ea 1/4X20 T-nuts

1 ea 1/4-20 X 5-6” bolt or all-thread

rod

3 ea - 1” X 1” flat metal - 1/16” - 1/8”

thick

12” of 3/4” dowel

tube of RTV cement

roll of Duck Tape

1 piece of plywood...3/4” X 14” X 28”

a few small tacks or small screws...say

10 each

3 ea # 10 panhead wood screws approx 1”

long

a bit of wood glue for the dowels

some flat black paint - spray can is

fine

The tools you will need...

a router with a circle cutting

jig...this can be made from 1/4” hard-

board or luan plywood

a set of drill bits and a power drill

(Continued on page 6)

Page 4: Star Gazer Newsdelmarvastargazers.org/newsletter/news2014/jul2014news.pdfJuly 2014 Page 1 Volume 21 Number 01 Star Gazer News Newsletter of the Delmarva Stargazers From the Prez…

July 2014 Volume 21 Number 01 Page 4

A Glorious Gravitational Lens

By Dr. Ethan Siegel

As we look at the universe on larger and larger scales, from stars to galaxies to groups to the largest

galaxy clusters, we become able to perceive objects that are significantly farther away. But as we con-

sider these larger classes of objects, they don't merely emit increased amounts of light, but they also

contain increased amounts of mass. Under the best of circumstances, these gravitational clumps can open up a window to the distant

universe well beyond what any astronomer could hope to see otherwise.

The oldest style of telescope is the refractor, where light from an arbitrarily distant source is passed through a converging lens. The

incoming light rays—initially spread over a large area—are brought together at a point on the opposite side of the lens, with light

rays from significantly closer sources bent in characteristic ways as well. While the universe doesn't consist of large optical lenses,

mass itself is capable of bending light in accord with Einstein's theory of General Relativity, and acts as a gravitational lens!

The first prediction that real-life galaxy clusters would behave as such lenses came from Fritz Zwicky in 1937. These foreground

masses would lead to multiple images and distorted arcs of the same lensed background object, all of which would be magnified as

well. It wasn't until 1979, however, that this process was confirmed with the observation of the Twin Quasar: QSO 0957+561. Gravi-

tational lensing requires a serendipitous alignment of a massive foreground galaxy cluster with a background galaxy (or cluster) in

the right location to be seen by an observer at our location, but the universe is kind enough to provide us with many such examples

of this good fortune, including one accessible to astrophotographers with 11" scopes and larger: Abell 2218.

Located in the Constellation of Draco at position (J2000): R.A. 16h 35m 54s, Dec. +66° 13' 00" (about 2° North of the star 18 Dra-

conis), Abell 2218 is an extremely massive cluster of about 10,000 galaxies located 2 billion light years away, but it's also located

quite close to the zenith for northern hemisphere observers, making it a great target for deep-sky astrophotography. Multiple images

and sweeping arcs abound between magnitudes 17 and 20, and include galaxies at a variety of redshifts ranging from z=0.7 all the

way up to z=2.5, with farther ones at even fainter magnitudes unveiled by Hubble. For those looking for an astronomical challenge

this summer, take a shot at Abell 2218, a cluster responsible for perhaps the most glorious gravitational lens visible from Earth!

Learn about current efforts to study

gravitational lensing using NASA facili-

ties: http://www.nasa.gov/press/2014/

january/nasas-fermi-makes-first-gamma-

ray-study-of-a-gravitational-lens/

Kids can learn about gravity at NASA’s

Space Place: http://spaceplace.nasa.gov/

what-is-gravity/

Abel 2218. Image credit: NASA, ESA,

and Johan Richard (Caltech). Acknowl-

edgement: Davide de Martin & James

Long (ESA/Hubble).

Page 5: Star Gazer Newsdelmarvastargazers.org/newsletter/news2014/jul2014news.pdfJuly 2014 Page 1 Volume 21 Number 01 Star Gazer News Newsletter of the Delmarva Stargazers From the Prez…

July 2014 Volume 21 Number 01 Page 5

Double Take Doug Norton

I have been an avid double star ob-

server for as long as I have been looking

through a telescope. Over the years I have

found nice pairings of double stars next to

famous objects we observe regularly and be-

low is a short list of the best. Because

the more popular objects steal the spot-

light these gems often go unnoticed. Hope-

fully the next time you are out looking at

these objects, you'll take a few extra min-

utes to seek out these unique pairings.

The designation of STF is an abbre-

viation for stars in the Struve catalog

discovered by Fredrich Georg Wilhelm

Struve. His son, Otto Wilhelm Struve has

the designation STT.

STF 1386 - This little multiple star

system rests right off the limb of M81.

We're always concerned with getting both

M81 and M82 in the same field of view but

we never really look beyond them at their

surroundings. This multiple isn't usually

listed or plotted on any chart. But all you

need to do is just center M81 and do a lit-

tle sweep around the arms and you should

pick them up with ease. What we have is an

AB pair making up the brighter of two pairs

of stars, a true binary star. The CD pair

are right next to the AB pair. However, the

D component is the true binary but it is

magnitude 17. SAO 15018 is the visual bi-

nary you see next to the C component. It is

simply line of sight but makes for a nice

double-double with the AB pair, similar in

appearance to double-double in Lyra.

STF 272652 (52 Cyg) - This guy is

right smack in the middle of the bright

West arm of the Veil Nebula in Cygnus. We

use this star to help us find the Veil but

never really look at it. It is a wonderful

double because of the color contrast and

the large differ-

ence in brightness

between the two

components. Bright

yellowish primary

with very faint

blue/white secon-

dary. This is one

of my favorite dou-

ble stars that most

people never real-

ize it is a double and they look at it all

the time.

STT 525 Lyra - Less than a low power

field sweep above the Ring Nebula, M57 in

Lyra lies one wonderful pair of stars. It

is truly a clone of Albireo in Cygnus. An

easy wide pair

of nearly equal

magnitude stars

that should be

easy in any

scope. A low

power eyepiece

will show it

with a nice

background of

field stars.

STF 742 - This is a fine little dou-

ble star

right next

to M1 Su-

p e r n o v a

r e m n a n t .

Tight com-

p o n e n t s

yet easily

split with

m e d i u m

powers. Both components are equal magni-

tudes with brilliant white colors. Really

nice and makes a unique field companion to

M1.

STF 1930 (5 Ser) -

This double star

rests right next to

the amazing globu-

lar cluster M5 in

Serpens Caput. It

is in the same

field of view as M5

with a low power

eyepiece. The pri-

mary is an ivory color while the secondary

is too faint to detect any color. I always

love observing these two next to each

other.

Page 6: Star Gazer Newsdelmarvastargazers.org/newsletter/news2014/jul2014news.pdfJuly 2014 Page 1 Volume 21 Number 01 Star Gazer News Newsletter of the Delmarva Stargazers From the Prez…

July 2014 Volume 21 Number 01 Page 6

a wood saw...back saw preferred butt

most any hand saw will work

a metal cutting hacksaw

My mirror cell is simply two identi-

cal round circles cut with the router. One

holds the mirror, the other is secured to

the telescope tube with 3 screws.

The cell is a Push-Pull arrange-

ment...3 of the machine bolts push against

the mirror support and the other 3 pull the

mirror support to the tube board. This

will lock the mirror in place. I prefer it

to a spring loaded arrangement that uses 3

bolts instead of 6.

The push bolts push against a thin

piece of metal screwed to the back of the

mirror support.

Tee Nuts provide the beginning points

for the push/pull force. The 7th Tee

Nut...in the center...provides a place to

secure the long 1/4x20 bolt used in deter-

mining where to mount the primary...more on

that later.

The three

vertical dowels are

split to provide a

flat surface to fit

the mirror edge.

There is a small

hole in each to

provide for adding RTV cement twixt the

dowel and the mirror.

I like to further secure my mirror to

the cell with 2-3 wraps of Duck Tape.

The final arrangement of mirror sup-

ports is the choice of the maker...3

points of RTV cement pads, 9 point flota-

tion, or more points of flotation.

Small holes can be added in the ply-

wood discs for ventilation without changing

the rigidity of the cell.

Total time to make this type of cell

is approx 3 hours. There are several

variations...one uses metal clips vs the

dowel posts. I prefer the dowel post be-

cause the metal clips interfere with the

surface of the mirror, ie, they place 3

huge “scratches” on your mirror surface.

Witness marks are added for any dis-

assembly / reassembly.

Oh... determining where to mount the

mirror. I follow this procedure when con-

structing a telescope.

1. Mount the spider at least half the tube

diameter inside the tube

2. Mount the secondary to the spider to de-

termine where the focuser should

be...then remove the secondary

3. Drill the holes for the focuser and

mount it

4. Remount the secondary directly under the

focuser

5. Take the OTA and mounted primary to a

site where there is an object at least a

couple of miles away to focus on...a

water tower works well

6. With the primary mounted in its cell and

with the long 1/4X20 bolt attached for

use as a handle, shove the primary into

the tube

7. Put a 25-30MM plossel eyepiece in the

focuser and rack it about half in/out

8. Then move the primary forward/backward

until the target is focused

9. Measure the distance from the back end

of the tube to the back of the mirror

cell and write this number down...sos’n

you don’t forget it

10. Then take your telescope home and mount

the mirror into the tube with the 3 pan-

head wood screws...and use some washers

twixt the panhead and the outside tube.

Note: Please pay attention here and

mount the primary perpendicular to the

tube!

Good luck and happy viewing.

(Continued from page 3)

Page 7: Star Gazer Newsdelmarvastargazers.org/newsletter/news2014/jul2014news.pdfJuly 2014 Page 1 Volume 21 Number 01 Star Gazer News Newsletter of the Delmarva Stargazers From the Prez…

July 2014 Volume 21 Number 01 Page 7

The Delmarva Stargazers’ Club Picnic

will be July 12th at Don and Karen Surles’ home starting at 1 PM. The address is 514

Marilyn Rd., Smyrna DE. If you need help call 302-653-9445.

You are welcome to bring a covered dish or desert but it is

not a requirement for attendance. You are also welcome to bring fam-

ily, friends or anybody who would like to meet us.

We'll supply burgers and dogs, corn-on-the-cob, condiments,

soda and water. Please join us as we celebrate another successful

year of the Delmarva Stargazers Amateur Astronomy Club and the great

country we live in.

Please bring chairs. A tent will be available if the sky is

not blue.

Building a Telescope

Step by Step: Step One- Mirror By: Sean Lutz-Swank

For any stargazer whether you’re

young, old, an amateur or a professional,

the idea of building your own telescope

seems like the golden idea. Imagine taking

your homemade telescope out to a stargazing

party or meeting up with some friends and

the conversation turns from “What are you

going to look at?” to “How did you make

your telescope that light but sturdy?”

Your telescope will be the center of atten-

tion. However, just like any dream or goal,

they are steps you must take. This is what

I am currently doing and will keep doing

until my telescope is done. I will give you

my perspective along each step of the way.

Now let’s begin with the first step.

How can you use a telescope without a

mirror? That would be like using a car

without an engine. All you have is just an

optical tube and a mount. The first step in

many is figuring out how big you want your

mirror to be. The primary mirror can be any

size from a 4-inch to an 18-inch and even

bigger than that. But for now, I’m using an

8-inch mirror. When the idea of building my

own telescope came to me, I was ecstatic.

But first the mirror had to be made.

I already had a 4-inch Celestron I

had bought off the internet. So I chose an

8-inch since it would give me double the

light-gathering area of my 4-inch. The Del-

marva Stargazers Club, which I am a proud

member of, held a mirror making seminar or

MMS. This was my first MMS so I was nerv-

ous. But my fellow members made it seem

much more fun than what I imagined it to

be. The first day of the MMS was in my

opinion the most difficult. Like I said I

had never done this before so I was pre-

pared for what was going to happen. After

the first day of grinding a “tool” mirror

across my own mirror, my arms felt like

they were going to fall off.

I started out using a “tool” mirror

to grind down my mirror to a parabolic

curve. Both my mirror and the “tool” mirror

were pieces of cut glass. I used different

size grit to grind down my mirror to a

smooth finish. I couldn’t finish it in the

four days the MMS was taking place due to

some prior commitments. At one point, I

honestly felt like this was too much for

me. But I have to give my fellow club mem-

bers credit for convincing me to keep go-

ing. So I just kept at it and it turned out

to be quite fun. I had the help of quite a

few people giving me tips and keeping me

focused. However, on the last day of the

MMS, I couldn’t finish polishing my mirror,

so I asked if one of the members if he

could finish it for me. He did and I thank

him for doing that.

After the mirror was grounded down

and polished, the next step was to get the

shiny, reflective coating of aluminum. Now

getting a coating of aluminum on a mirror

isn’t as easy as one might think. You have

to use pure aluminum inside a vacuum sealed

chamber and run electrical currents through

the filaments of aluminum to melt them and

then coat the mirror. So where would we get

that done at? The closet aluminizing place

was in New Jersey about one hour south from

New York City. Since there were about 12

mirrors that needed to be coated it was

cheaper to drive there than send them there

via the mail. So that meant one thing, road

trip! With some predicted and unpredicted

situations, we eventually took the mirrors

and got them coated. So now that the mir-

rors are coated we can finish step one of

building a telescope and start on the sec-

ond step, designing the telescope.

Page 8: Star Gazer Newsdelmarvastargazers.org/newsletter/news2014/jul2014news.pdfJuly 2014 Page 1 Volume 21 Number 01 Star Gazer News Newsletter of the Delmarva Stargazers From the Prez…

July 2014 Volume 21 Number 01 Page 8

How to Join the Delmarva Stargazers: Anyone with an interest in any aspect of astronomy is welcome NAME_____________________________________________________________New (y/n)____Renew (y/n)______ ADDRESS_____________________________________________________________________________________ CITY, STATE & ZIP______________________________________________________________________________ E-MAIL ADDRESS (If any)_________________________________________________________________________ Do you need the newsletter snail mailed to you (Y/N)?___________________________________________________ Please attach a check for $15 made payable to Delmarva Stargazers and mail to Kathy Sheldon, 20985 Fleatown Rd, Lincoln, DE 19960. Call club President Lyle Jones at 302-736-9842 for more information.

Keeping Logbooks Doug Norton

When I first began observing the

night sky I was just 15 years old. It was

July 1987 and I had just purchased my very

first scope, a Jason 60mm refractor on a

spindly German Equatorial Mount (GEM). I

had worked part of the summer painting my

aunt's house in order to afford it. One of

the first things I ordered through the mail

was a book to help me find my way around

the sky. That book was called "Leslie

Peltier's Guide to the Stars, Observing the

Sky With Binoculars". It inspired me in

more ways than I can count.

First, it taught me to truly appreci-

ate the sky and all its wonders. His writ-

ing was passionate and inspiring. Second,

it taught me to keep a journal of all the

objects I had seen. In the back of the

book, the author had laid out lists in the

appendices of the constellations, the

brightest stars, double stars, nebulae and

clusters, variable stars, the planets, as-

teroids, meteor showers and the moon. He

called it the "Life List of Celestial Ob-

jects". Next to each entry were spaces for

entering the date of seeing the object as

well as a space for comments. Well, I did-

n't want to write in my book, I wanted to

keep it as new as possible so I hunted down

a journal and copied all of the lists of

objects into it. Thus began my diligent re-

cord keeping of everything I was seeing for

the first time, the dates I saw them and

any comments I had. At the time my comments

were very brief, if I put any down at all.

Over the years they have become much more

descriptive.

Years later, as I started looking

through my logs I noticed that there was

something missing that the logs just didn't

capture. The logs had captured the dates

and the descriptions of the objects but

there were more things going on during the

observing sessions than the logs could cap-

ture. Things like observing locations,

weather conditions, people in attendance,

bollides, aurora, comets, how long the ob-

serving sessions lasted, etc. Just a gen-

eral overall synopsis of the evening. So I

started writing a synopsis of each evening

along with all the logs I kept.

For me, keeping these logs and writ-

ing these summaries for each observing ses-

sion has been invaluable. Not only do I

have a record of what I saw but I have cap-

tured the evening forever. It also has

helped me to see a progression in my ob-

serving skills over the years. And every

time I look at an object I've seen a thou-

sand times before, I always see something

new. I go back often and read over my writ-

ings and am able to remind myself of who

was there, what we saw, what gear people

were using at the time and more. A bit of

nostalgia. Currently I have more than 1700

log entries and over 45 pages of evening

summaries. I try to inspire others to keep

logs of what they see. I think that any

kind of record, such as drawing, recording

your voice, writing in a journal or typing

away on a computer is important. I am con-

stantly asked if I have ever seen NGC so

and so and what I thought of it. All I have

to do is look up in my logs and I can tell

you the dates and my impressions.

I still have my first book and my

first log book. I have long since tran-

scribed all the entries into the computer

but every once in a while I'll pull them

both off the shelf and thumb through them

and it takes me back to those first nights

under the stars all those years ago.