Download Binary Beauties: By John R - Black River Astronomical Society

Lorain County, Ohio
February 2015
Website: blackriverastro.org
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Newsletter submissions: Editor
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Wednesday, February 4, 7 p.m.: Regular monthly meeting, Carlisle Visitors
Center. Program: Using the Sky&Telescope Sky Guide (guides provided)
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Thursday, February 12, 7 p.m.: Board Meeting, Blue Sky Restaurant,
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Sunday, February 15, 6:30-8:30 p.m.: Nighttime Stargazing Walk, Wellington
Reservation
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Friday, February 20, 7-9 p.m.: Public observing, Nielsen Observatory
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Saturday, February 21, 7-9 p.m.: Backup date, public observing
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BOARD SUMMARY, January 15, 2015
The meeting was called to order with eight Directors present. The
minutes of the December meeting and Dan Walker's Treasurer's report were
both read and approved and it was time for committee reports. Bill Ruth, the
Guidescope editor, reported that all is well with our newsletter. Lee
Lumpkin reported that the website, forum and gallery are all working well,
although he fixed a broken link recently, and John Reising as head of the
Instrumentation committee reported that everything in the observatory was
in fine shape. The OTAA committee reported that we have been able to secure
the Birmingham Methodist Church Hall for our OTAA convention on Sept. 12,
2015. This has been our OTAA “home” for many years. This year the church
moved us to “Public Service Organization” status and offered us the hall
for free. They did, however state that donations were gladly accepted, so we
donated $100. The MetroParks Liaison had no report.
Programming is set through August with BRAS members interested in
giving a program asked to contact any Board member. Our programs will be:
February--Dave Lengyel--Using the Skygazers Almanac (a copy will be given
to all who attend).
March--John Reising--Messier Marathon
April --Steve Schauer--The BRAS Year in Review and coming events
May--Kelly Ricks --TBA
June--Dave Lengyel--Old School slide presentation
July--Dan Walker--Equation of Time
August--Len Jezior--Optical Filters: Why, How and When?
Under Old Business, Schauer reported on the progress of the Worldwide
Solstice Festival Committee and stated that the Board needed to form a
Publicity Committee soon. He asked that Board Members think about methods
of getting publicity for the Festival and that we form such a committee at
the next meeting.
The most time was spent on setting the dates for Public Observing for
2015. The dates and times have been set and have been sent to Tim
Fairweather so that they can be put in the Lorain County MetroParks
newsletter, the Arrowhead. Lee Lumpkin will also enter them into the BRAS
calendar.
There was also a brief discussion about Charlemont permits for
members who want them. Charlemont is a MetroParks reservation in southern
Lorain County, south and a little west of Findley State Park. It is
unimproved, consisting of a gravel parking lot and hiking trails. It is
closed at night unless one has a permit to use the property. The draw here
is that the skies are very dark with few lights in the area. The LCMP
Liaison, Steve Schauer, will contact the Parks to see if we can get six
permits. This way any members who want to travel to Charlemont to observe
or photograph only need one of the permit holders to accompany them. We
will try to get permits in the hands of members who are retired and who
live in central or south Lorain County as they would be the people most
likely to be available.
There was only one item of New Business. This was a discussion of
Comet Lovejoy and trying to hold an observing session for the public. We had
Public Observing planned on the 16th and 17th, but we decided that if those
dates were clouded out, we would try to contact the LCMP about an impromptu
Public Observing session the next weekend (the 23rd,24th). Those dates would
not be in the Arrowhead, but they could be put on the MetroParks website and
Facebook page and we would do the same.
UPDATE: Friday the 16th was cloudy, but we were able to observe on the 17th
and got a good look at the comet. Lee Lumpkin and John O'Neal photographed
Lovejoy and others used binoculars and telescopes to observe. In the C-14
with a 55mm Plossl, a tail was visible.
Dates were read for January and February and the meeting was
adjourned.
--Steve Schauer
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WANTED: Clock-driven equatorial mount for 10" tube. Can be
slightly larger or smaller than for 10". Contact Len Jezior
[email protected] (440) 453-8444.
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A LOOK AT EYEPIECE FILTERS
Many fellow amateur astronomers rarely use eyepiece filters during their observations. I'm not sure why, but
they're missing out on "better" viewing. In fact, simple color filters and more complex band filters can greatly
enhance images. It must be said at the onset that by their very nature, all filters reduce light. This characteristic
suggests filters are not recommended for use on small telescopes, those rated with very high f -numbers or when
using high magnification.
Filters fall within two categories, band specific & neutral density. Starting with "band specific" filters, these are
designed to influence light within a specific range or frequency.
Among the more complex, first and foremost is the broadband filter. A nebular filter strongly rejects the light of
sodium and mercury-vapor lights as well as natural airglow and auroral emissions. Conversely, the strong
nebular emission in the visual regions of 486nm (Hydrogen Beta, or Hß) and 496 to 501nm (Oxygen-III, or
OIII), are passed through the filter with high percentages. The effect is that nebular light reaching the eye is
dramatically increased in detail, while the effects of city light pollution are greatly reduced.
Unless you're observing from some distant mountaintop or desert, light pollution is a problem nearly
everywhere. The narrowband filter's primary application is in reducing light pollution with remarkable results.
This filter passes the two spectral lines of Oxygen III at 496 and 501nm and the Hydrogen Beta line at 486nm
while rejecting all others. Nearly 100% of city light emissions are rejected in this way while favoring nebular
artifacts.
Both narrow and broad band filters result in significant overall light reduction. Best results occur in using these
with lower magnification (no Barlows) and/or with scopes rated with a 15 f-number or less. While neither filter
is meant for photographic application, they can still be applied to digital cameras with satisfactory results. The
highly reflective surfaces of these filters can induce aberrations when applied with other filters and when
performing long time exposure photography.
Another type of band influencing filter are color filters. One might think that filtering a color range would yield
little improvement, but it can. These filters are quite inexpensive and easy to apply with a basic understanding of
the artist's color wheel.
Briefly reviewing this feature, there are 3 primary colors, red, yellow & blue. Between these 3 are 3 secondary
colors created by blending 2 adjacent primary colors... orange (red + yellow), green (yellow + blue) and purple
(blue + red).
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RED
PURPLE
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ORANGE
X
BLUE
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YELLOW
GREEN
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These 6 colors are arranged in a circular or clock-like format starting with red at the 12 o'clock position and
green at 6. In this hexagonal framework, the colors facing opposite sides of the wheel are termed
"complementary" colors. Complementary colors blended together make a dark gray (black).
Using color filters exploits this characteristic. For example, Jupiter's predominant color is orange, Mars, a rusty
red. By using a filter of complementary color, blue (or green), the red-orange hue appears darker, more grayish
in appearance. This will produce a higher contrast or distinction between the remaining white, brown, yellow
and blue hues. The overall image will take on the color of the filter but if you're creating digital photos, this
coloration can be adjusted later, leaving natural colors of higher definition. The key to successful application is
in using a filter of complementary color to the general overall color of the object. That's the short and long of it...
no real trick and it works well with both camera and naked eye observation.
Polarized & Neutral Density filters...
There are two types of polarized filters serving two different purposes. First, the simpler of the two uses a single
layer of polarized material. Application is meant for observing the Moon or deep space gaseous artifacts. By
rotating the filter at the eyepiece or camera, the object's reflective properties can be manipulated to produce
artificial color and increased contrast.
The second polarized filter type is comprised of two layers of polarized material. The 2nd layer is mounted
immediately above the 1st and is meant to be rotated. The filter is designed to act as a light "spigot", able to
meter incoming light. As fields cross, the filter darkens. This is handy to reduce the amount of light presented at
the eyepiece for lunar and terrestrial observation. (WARNING: Never use these for solar observation.)
Other light reduction filters include the neutral density white light or "smoked" solar filter. These are typically
made of either Mylar film or glass. While both are considered equally effective, my personal preference leans
towards glass. While more expensive than Mylar film, I find them easier to clean, less likely to puncture, less
vulnerable to other damage and less likely to cause distortion. This filter is installed at the telescope's primary
objective, not at the eyepiece. Like a welder's mask, this filter is designed to reduce the intensity of visible light
as well as reduce harmful infrared and ultraviolet emission. It also protects the image train from the intense heat
produced by magnification of the Sun's rays. A split second exposure to unfiltered solar radiation will
permanently injure the eye and can instantly damage the camera and telescope components. Solar filters should
be installed or removed while the telescope is oriented in a direction looking away from the Sun. Guide scopes
are often overlooked. Be sure they're capped or filtered as well. Even if an uncapped guide scope isn't being
used, misdirected sun rays can melt or burn components and optical coatings.
Solar observation frequently employs the use of special devices or single purpose telescopes. These are designed
for singular application to dramatic and even spectacular effect. This, however, is a topic unto itself.
With the exception of the front-mounted solar filters, eyepiece filters screw onto the inward side of an eyepiece.
However, if you're using an erecting prism, you can attach the filter there. This precludes the need to remount a
filter each time you change eyepieces. Also, if you're looking downwards into the eyepiece during observation,
another "trick" is to simply drop the filter into the eyepiece's relief cup. This is a fast and easy way to change
filters, testing to see which color filter produces the best effect. Since the filter glass has no light-bending
qualities, (or at least it shouldn't have), it doesn't matter where within the image train it's located. This makes for
as simple use as can be expected.
Eyepiece filters are easily found at any telescope accessory website. Buying a "set" of color filters is usually
preferred and certainly saves $$$. Prices vary widely so shopping around is recommended but remember, quality
counts.
Lastly, color filters are not recommended if you're using a monochromatic camera with RGB filters. As you can
imagine, a mix of color applications will produce severely negative effects. Color manipulation is much more
effective at the post processing stages where color layers can be enhanced or reduced.
In summary...
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All filters significantly reduce light at the eyepiece.
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Band pass/reject filters help reduce light pollution & enhance contrast.
Color filters are best applied using the color complementary to the object's overall color.
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Polarized filter are used primarily to meter light, increase contrast or create false color.
NEVER do solar observation without the proper use of solar specific filters or scopes.
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Solar filters are best applied at the scope's primary objective--including guide scopes.
Solar observation is inherently dangerous to eyes & equipment. Supervise children.
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Color filters are counterproductive with monochromatic imagers using RGB filters.
~Len Jezior
Comet Lovejoy, January 13, 2015
photo by Dave Lengyel
The History of Naming Heavenly Bodies
February brings Valentines Day. While this holiday bring love to the air, it also bring scams of
astronomical proportions.
Every now and then, especially on late night radio or TV this time of year, one will come across
an ad where a business promises to, for a fee, rename a star after your special someone. Cash paid, one
will then be mailed an official certificate stating that, indeed, some celestial body is now named after
your significant other. Sounds cool doesn't it?
Unfortunately, it's all a scam.
When it comes to naming heavenly bodies, the International Astronomical Union (IAU) is the
only body who's opinion matters. In the past, naming things in space was a kind of Wild West, if you
will. At one time, any body or feature on a body was named by whoever discovered it. Usually, the
names were respectable and the astronomical community went along with them. However, a turning
point came in 1781 when British astronomer William Herschel discovered a planet beyond Saturn.
Being a patriotic Englishman, for Herschel, it was only natural to name the new planet after then-king
George III, who was so flattered that he became Herschel's patron after the discovery. Herschel's
proposed name for the planet: Georgium Sidus (the Georgian Star). However, for people of other
nationalities, especially the French, the name wasn't too popular. Not surprisingly, astronomers of other
nations didn't adopt Herschel's suggestion for the king-honoring name, opting to call the planet
'Herschel' instead. In time, though, in keeping with tradition, the 7th planet was named Uranus, the
Latinized version of the Greek sky god's name, Ouranos. Why Uranus? Simple. Saturn (6th planet) was
the father of Jupiter (5th planet). So, in keeping with this father-son trend, it was only natural that the
7th planet should be named for the father of the 6th, which, by default, would be Ouranos (Uranus),
who was the father of Saturn.
By 1850, Uranus was finally the accepted as the name for the 7th planet (8th planet Neptune
being discovered two years previously).
So, after the decades-long Planet George/Herschel mess, the rules for naming things in space
became more clearly defined as the international community decided as a whole that the names for
bodies in the cosmos should not reflect national chauvinism on Earth. In time, these unwritten rules
would evolve into the formal procedures of today where only the IAU, not late-night advertisers, can
approve the name for any cosmic body.
In conclusion, next time you hear an ad where, for a fee, you can name a star, asteroid, or
whatever after your special someone, don't only ignore the ad, but then warn your friends of such
scams.
~Denny Bodzash
Comet Lovejoy and M13, January 19, 2015
photo by John O'Neal
Binary Beauties
Below is a star chart and a short table with the names, locations and specifications
For some of the brightest and easiest binary stars visible in the mid to late winter evening sky.
The table includes the following:
ADS number: From the ADS double star catalog.
Name: Greek letters, (mostly), or numbers with constellation.
Celestial Longitude: (RA) & Celestial Latitude: (DEC): for those with equatorial mounts
with setting circles.
Star Magnitudes: Primary star first & companion star next.
Position Angle, (PA): Position of companion relative to the primary star:
0 deg = North; 90 deg = East, 180 deg = South; 270 deg = West.
Separation, (“ = arc seconds): Distance between the primary and the companion star.
Included on the list are the following, which I consider as some of the absolute finest binary stars in the
heavens,
(alpha), a Gemini: Castor!! A white / white pair stars with magnitudes of 1.9 & 2.9 at
a distance of nearly 4 arc seconds. Wonderful in even the smallest of telescopes but may
present a glare problem in some small scopes!
(delta), d Gemini: A bright white primary and dim yellow-orange companion well
below Pollux about ½ the down the left string of stars in Gemini. Some magnitude
difference, (3.5 & 8.0), but separable, ( 6.3 arc seconds), in medium sized telescopes.
(beta), B Monoceros: A stunning triple star of 3 blue-blue 5th magnitude stars just
above Sirius and to the left and below Orion’s belt. Magnitudes, separations and
position angles listed below:
4.5 & 5.4
7.3”
132 deg
5.6
2.8”
106 deg
(epsilon), e Monoceros: A nifty pair of white stars just left and slightly below
Betelgeuse, (alpha Orion) and just to the right of the “Rosette nebula”. Magnitudes of
4.4 and 6.7 with a separation of 13.3 arc seconds puts this pair within the reach of even
small instruments.
(zeta), z Cancer: A challenging triple star system of 3, 6th magnitude stars with a white
primary and 2 yellow companions, one of which is a mere 1.0 arc second from the
primary. Very, very difficult to split the 1 arc second pair. Magnitudes, separations and
position angles listed below:
5.6 & 6.0
1.0”
59 deg
6.2
6.0”
72 deg
(iota), i Cancer: A very nice “Albireo” class double straight above the M44,
(“Beehive”), cluster. A yellow-orange and blue pair at 4th & 7th magnitudes with a
separation of 30.5 arc seconds.
~John Reising