AAGG Show #22: Show Notes

Carpe Noctem - Seize the Night!

photo courtesy of: Ron Wright
Grand Rapids MI

Can You Count the Stars Tonight?

My darling daughter, can you count the stars tonight?
Can you imagine a night, not so long ago, filled with starlight,
An infinity of shimmering diamonds on a meadow of velvet?
Can you close your eyes and picture a river of a million distant fireflies,
A cascade of sparkling heavenly beacons that once filled our skies?
Now that those who are without wonder or awe have taken our night,
My darling daughter, can you count the stars tonight?

Yes, daddy, I can see two!
---Doug Snyder, 5 August 1998

Listener Question

Ron, from Grand Rapids MI, is looking for E.T :-) 6.4 mag NGC 457 in Cassiopeia it doesn't have a "M" number but it isn't too hard to find. NGC 457not a good picture - too many stars! near M103 (7.4 mag NGC 581)

Also Anthony from Manchester is getting ready to go on holiday and sent in the following request:

"Hi Alice,

I will soon be going away on holiday with the family for a couple of
weeks and I wondered if you could throw out a question to your
listeners for any suggestions or recommendations for holiday reading?

Something reasonably light, in terms of weight and content, and
astro-related would be great. I won't have access to my scope and I'll
be most likely reading when its light (and hopefully sunny) so nothing
that requires any specific observing as I read. 

Cheers!  Anthony"

So leave your suggestions for Anthony in the show notes!

Viewing

Naked eye - May 27 - use binoculars (after sunset)to see a very young moon next to Mercury
May 30 - Moon and Mars line up with Castor and Pollux
May 31 - Waxing Crescent Moon, Saturn and the Beehive cluster all framed together

Binocular - M3 (6.3 mag) globular cluster half way between Cor Caroli and Arcturus about 12 degrees on the line starting from Arcturus
Jewel box in Crux (4.2 mag), Omega Centauri (3.9 mag), M7 Ptolomey's Cluster (3.3 mag) in Scorpio and M4 (5.4 mag) west of Antares.

Telescope - M63 The Sunflower Galaxy (8.5 mag), M94 in Canes Venatici(8.1 mag), and M51 the Whirlpool in Ursa Major all of which have very bright centers.
Compare these to M109 (9.8 mag) in Ursa Major Ringtail Galaxy (10.3 mag)NGC 4038 in Corvus and compare that to M104 (8.3 mag) Sombrero Galaxy on the border between Virgo and Corvus. For me this is still pretty far south in the light pollution and muck.

The Moon

Images created with Lunar Phase Pro

What to look for!
Waning and waxing crescent 2 days apart

Southeast favoring libration will help those with eagle eyes find some lunar edge items!

New! To help those working on Lunar awards* I will give latitudes and longitudes when possible. Remember latitudes that are negative (-) are South and longitudes that are negative (-) are West!

Object	Latitude	Longitude	Comments
Mare Australe	-38.9	93!
Mare Spumans	1.1	65.1
Mare Undarum	7	69
Crater Petavius and rimea	-25.1	60.4	Rimea Petavius a straight line from the central peak SW
Crater Langrenus(lan-grin'as)	-8.9	61.1	During the Apollo 8 mission, Astronaut James Lovell described Langrenus as, "quite a huge crater; it's got a central cone to it. The walls of the crater are terraced, about six or seven terraces on the way down." The Flemish Astronomer Michel Florent van Langren was the first person to draw a lunar map while giving names to many of the features. He even named this crater after himself. Ironically, this is the only one of his named features that has retained his original designation *Wikipedia entry Langrenas is also a site with a history of transient lunar phenomenon (tlp)
Crater Cleomedes	27.7	56	Just above Mare Crisium it is named after the 1st century Greek astronomer known for his book On the Circular Motions of the Celestial Bodies. Crater Cleomedes is a very prominent crater approximately 126 kilometers in diameter with rilles on the central peak and sides.
Crater Hercules	46.7	39.1	With twin crater Atlas...
Crater Atlas	46.7	44.4	With twin crater Hercules...look for the dark halo craters

*Lunar Awards:
Astronomical League Lunar Club and Lunar Club 2
Lunar 100 - Charles A. Wood- 100 features laminated feature card available through Sky and Telescope
Free online support at Charles Wood's site and Mike Tyrrel site (lots of pictures slow to load)
Astronomy a Go Go! Lunar club (The loonies?) coming soon 4 levels; beginner, intermediate, advanced and master. No membership required no fees, beautiful "you print" certificate for each level and your name on the website.

Planets

Evening Planets
• Jupiter - Mag -2.5 in Libra. Just past opposition for those of you watching this gas giant over the past couple of months will have noticed it getting brighter. Clearly visible just after sunset, if you know where to look! The bright star to the SE is Zuben Elgenubi in Libra the bright star west along the ecliptic is Spica in the constellation Virgo. Any telescope can reveal its two widest cloud bands and four Galilean satellites.
  Listener Kevin recommended a piece of free software that I now have on all my computers Jupiter 2.
• Saturn - 0.1 mag In Cancer and tonight and moving East just 1.5 degree SW of M44 the Beehive cluster. It appears as a yellowish star that rivals Capella in brightness, A small telescope will always show Titan, Saturn's largest and most extraordinary moon.
• Mars - Mag +1.6 in Gemini creeping west towards Cancer and Saturn. It is the bright point of light SW of Castor and Pollux just SW of Kappa Gemini so that it looks like Pollux is trying to reach out and catch him.
• Mercury - has now finished his time behind the sun and has joined the rank of the evening planets. This weekend it will be very near the horizon just after sunset between the sun and the waxing crescent moon.
  Morning Planets
• Venus - Mag -3.9 The brightest morning planet visible. Low in the eastern morning sky. You will want to grab a pair of binoculars or even just a finder scope to check out her phase. Just over half full she is intensely bright in her gibbous phase.
• Uranus - Mag. 5.9 in Aquarius low in the south west before dawn.
• Neptune - Mag. 7.9 in Capricorn low in the south west before dawn
• Pluto Mag. 14 in Serpens Cauda is high in the south before dawn In Superior Conjunction - As alignment of an interior planet (Venus or Mercury) and the Sun which occurs when the Earth and the planet are on opposite sides of the Sun.
  

Viewing

Some things to keep in mind about our viewing difference:

• Location
• Age
• Ability/Experience
• Fatigue
• Instruments

Some things you can calculate and work around:

• Sky Brightness - The higher in the sky you look, the darker the sky will be. Plan your deep-sky observing projects accordingly. Also, light pollution tends to improve a bit after 11 or midnight as some outdoor lights get turned off.
• Dark Adaptation - After spending 15 minutes in darkness you might think your night vision is fully developed. But in fact your eyes gain as much as another two magnitudes of sensitivity during the next 15 minutes. Thereafter, dark adaptation improves very slightly for 90 minutes more. So don't expect to see faint objects at their best until a half hour or more into an observing session.
• Averted Vision -When you look directly at something, its image falls on your retina's fovea centralis. This spot is packed with bright-light-optimized cone cells and provides sharp resolution under strong illumination. To see something faint, you have to look slightly away from it. Doing so moves the image of your target off the fovea and onto parts of the retina that have more rod cells, which see only in black and white but are more light-sensitive than the cones.
• High Power - Can help bring out the detail of galaxies, clusters and nebula but can be thwarted by high sky brightness. Feel free to experiment!
• Capturing Color - In order to show us color, a deep-sky object must have a high enough surface brightness to stimulate the retina's cone cells Averted vision is not the way to look for color. The cones are thickest in the fovea, so stare right at your object. In this case, the lowest useful power should work best. A large telescope aperture is especially advantageous for those who seek to see color in deep-sky objects.

Weather charts and forecasts

Cloud cover This forecast may miss low cloud and afternoon thunderstorms. When the forecast is clear, the sky may still be hazy, if the transparency forecast is poor.

Transparency-Astronomically 'transparency' means just what astronomers mean by the word: the total transparency of the atmosphere from ground to space. It's calculated from the total amount of water vapor in the air. It is somewhat independent of the cloud cover forecast in that there can be isolated clouds in a transparent air mass, and poor transparency can occur when there is very little cloud.

Above average transparency is necessary for good observation of low contrast objects like galaxies and nebulae. However, open clusters and planetary nebulae are quite observable in below average transparency. Large globulars and planets can be observed in poor transparency.

Transparency Scale
0. Do Not Observe - Completely cloudy or precipitating.
1. Very Poor - Mostly cloudy.
2. Poor - Partly cloudy or heavy haze. 1 or 2 Little Dipper stars visible.
3. Somewhat Clear - Cirrus or moderate haze. 3 or 4 Little Dipper stars visible.
4. Partly Clear - Slight haze. 4 or 5 Little Dipper stars visible.
5. Clear - No clouds. Milky Way visible with averted vision. 6 Little Dipper stars visible.
6. Very Clear - Milky Way and M31 visible. 7 Little Dipper stars visible.
7. Extremely Clear - M33 and/or M81 are visible.

Seeing
Refers to the blurring and twinkling of astronomical objects such as stars caused by turbulence in the Earth's atmosphere. The turbulence can also come from the telescope itself, the observer, or the immediate surroundings.

Excellent seeing means at high magnification you will see fine detail on planets. In bad seeing, planets might look like they are under a layer of rippling water and show little detail at any magnification, but the view of galaxies is probably undiminished. Bad seeing is caused by turbulence combined with temperature differences in the atmosphere. This forecast attempts to predict turbulence and temperature differences that affect seeing for all altitudes.

Bad seeing can occur during perfectly clear weather. Often good seeing occurs during poor transparency. It's because seeing is not very related to the water vapor content of the air.

Astronomical Seeing
1. Severely disturbed skies: Even low power* views are uselessly shaky. Go read a good book.
2. Poor seeing: Low power images are pretty steady, but medium powers are not.
3. Good seeing: You can use about half the useful magnification of your scope. High powers* produce fidgety planets.
4. Excellent seeing: Medium-powers are crisp and stable. High-powers are good, but a little soft.
5. Superb seeing: Extremely Steady. Any power eyepiece produces a good crisp image.

* The PRACTICAL LOWEST power magnification for any telescope is approximately 7 times for each inch of aperture. Example: 28X for a 4-inch (100mm) diameter telescope
* The PRACTICAL HIGHEST power magnification for any telescope is approximately 50 times for each inch of aperture. Example: 200X for a 4-inch (100mm)diameter telescope.
Humidity

This forecasts ground-level relative humidity. Humidity variations won't determine whether or not you can observe, but it might affect observer comfort and can indicate the likelihood of dewing.

But dewing is not simply correlated to relative humidity. Dewing tends to happen when the sky is clear, the temperature is dropping and there isn't much wind. Being on a hilltop or in a small valley can make the difference between no dew and dripping telescopes.

An example of transparency forecasting from Environment Canada
Outside of North America try the 7timer site
In North America try Clear Sky Clock
Everyone can try Wunderground, here is an example of South America
Great Britain and Ireland can try The Weather Outlook they have a tab for astronomy and it seems to be improving. There is also MetCheck which loads faster and will take a postal code.

Limiting Magnitude

Apparent magnitudes How bright things look from Earth. We don't know how intrinsically bright an object is until we also take its distance into account. Thus astronomers created the absolute magnitude scale.

Absolute magnitude An object's absolute magnitude is simply how bright it would appear if placed at a standard distance of 10 parsecs (32.6 light-years) The parsec (symbol pc) is a unit of length used in astronomy. It stands for "parallax of one arc second". BBC's Sky at Night programme: Patrick Moore demonstrates Parallax using Cricket.

Seen from this distance, the Sun would shine at an unimpressive visual magnitude 4.85. Rigel would blaze at a dazzling -8, nearly as bright as the quarter Moon. The red dwarf Proxima Centauri, the closest star to the solar system, would appear to be magnitude 15.6, the tiniest little glimmer visible in a 16-inch telescope! Knowing absolute magnitudes makes plain how vastly diverse are the objects that we casually lump together under the single word "star."

Some online calculators of Limiting Magnitude and surface brightness.

News

ESA lava tubes on Mars. Mars Express, shows Pavonis Mons, the central volcano of the three 'shield' volcanos that comprise Tharsis Montes

ProAM extrasolar planet find!. In June and July 2005, four amateur astronomers (Ron Bissinger in California, Bruce Gary in Arizona, Paul Howell in Maine, and Tonny Vanmunster in Belgium) carefully monitored one of the most promising candidates identified by XO: a magnitude-11.3 solar-type star in Corona Borealis. The amateur observations revealed the telltale periodic dips of a transiting object only 30 percent larger than Jupiter. The star decreases in brightness by 2 percent for 3 hours every 3.9415 days  -  the companion's orbital period. Armatur Transit organization Transit.org

Comets for May.

"One touch of nature makes the whole world kin"
-- Shakespeare

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Music

28 -"Miles Away"
Katy Pfaffl -"Halfway There"

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