New Slacker Astronomy Episode

This week Doug, Michael and I have a lot fun talking about CCDs and how they work, we answer questions from the reader mail bag about cosmology and the expansion of the universe, and Michael introduces the new Slacker Blogger, Ben Huset. There are a lot of laughs in this one, and we wax a little philosophical here and there. Tune in to the Slacker Astronomy Podcast and join in the fun.

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Richard E. Wend (1921-2009)

By Roger Kolman

Dick Wend passed away Sunday, October 25, 2009, after a battle with lymphoma. For anyone who knew him a deep void now exists within. He will be sorely missed.

Dick was a member of the American Association of Variable Star Observers (AAVSO) for six decades and was a recipient of the Director's Awards for his lifetime contributions.

He was an avid observer of the planet Jupiter and served as the Jupiter Recorder for the Association of Lunar and Planetary Observers.

He was a longtime member of the Milwaukee Astronomical Society and the Racine Astronomical Society and served as in officer in the RAS for many years.

He was a member of the Astronomical League for more than six decades and served as an officer of the North Central Region for many years. Additionally, he served as a member of the Leslie C. Peltier Award Committee from 1980 until his death.

He served as a volunteer at Volo Bog and received awards for his contributions to that organization.

He served on the Fox Lake Library Board from 1991 until his death and was a valued member of that group.

Any organization he joined became richer for his participation.

He was a valued friend to all who knew him.

May he rest in peace.

Double Dipping- Autumn

Most nights, I race through my variable star observations, trying to log as many as I can get as fast as I can go, before the weather changes, I run out of steam or the Sun comes up. I hop from field to field; completely ignoring celestial wonders just a few degrees away. When the longer, clear, dry nights of autumn finally come, I am tempted to take a few extra minutes along the way to take in some sights and try new challenges.

Lets say tonight is one of those glorious clear, moonless, autumn nights. You�ve decided to stop and smell the roses along the way, but you�d still like to make some variable star estimates. Or maybe a couple friends or family have stopped by for a late dinner, and now they want to look through the telescope. You need a plan. 

Obviously, we�ll start in the west and north with targets that will begin to fade into the haze of the horizon if we don�t get them right away. Since it is still experiencing a record minimum, in magnitude and duration, I think we should be sure to observe R CrB first. This star could be considered a deep sky wonder itself. Usually visible in binoculars as an unassuming sixth magnitude star inside the �Northern Crown�, R CrB undergoes sudden, random fading episodes, sometimes to 14th magnitude. As of this writing, it is hovering just above 15th magnitude, where it has remained for longer than ever before in recorded history.  In the same low power telescopic field is the semiregular variable TT CrB, ranging from 10.9- 12.1, just north of R CrB. If you have a telescope large enough to see R CrB around 14.8, you may want to continue on from TT CrB to the bright 7th magnitude star to the NW, GCS 2039 0642. Just about 10.5 minutes north of that star is a faint, round 14th magnitude galaxy, NGC 6001. I�d put identifying this in the �challenge� category. To me it looks like a slightly fuzzy star, but hey, we�re just getting started.

Before you leave CrB be sure to at least check in your finder to be sure the recurrent nova T CrB hasn�t erupted. If it has, you�ll see a bright star forming a triangle with epsilon CrB and delta CrB. Stop everything at that point and send out an alert. Forget the faint fuzzies!

Much more impressive in a telescope is M5 in Serpentis. This is about as low as we want to go, and this is a better summer target, but the irregular variable Z Ser is only 38 arc minutes away, and this star is almost totally ignored by observers. AAVSO has very little data on it. The GCVS lists a range of 9.4-10.9, and a period of approximately 88 days, so it should be interesting and easy to follow. Why don�t you adopt this star into your program, and pick it up again in spring when it comes out of conjunction. It will give you an excuse to observe M5 on a regular basis without diminishing your serious variable stars observer status.

From there we swing north to the great globular M13 in Hercules. Even I�m not so jaded that I don�t like to take a few minutes to take in the finest globular cluster visible in the northern sky. But let�s not get carried away. Waiting for us about one and a half degrees NW is the fine Mira variable W Her. W Her varies from 8th to 14th magnitude, so it�s usually visible in an 8-inch scope, and always visible in a 10 or 12-inch.

About halfway to our next destination is an anonymous little star cluster in Lyra, easily visible in your finder scope. Just to the east of the two brightest stars in the cluster is CY Lyrae, a fun little U Gem star that is fairly active, outbursting into the 13th magnitude range every couple weeks or so. Even if it�s not visible tonight, you won�t have wasted your time visiting here. This one is off the well-beaten path of deep sky wonders. It�s a pretty well kept secret amongst variable star folk, and we aim to keep it that way, so shhhh�don�t tell anyone. 

If you have company at the observatory, M57 is one of the stops you�ll make anyway, so here is your chance to quickly locate and show them a real crowd pleaser, the Ring Nebula in Lyra. Located in the same low power view as the ghostly ring of this planetary nebula is another Mira variable RX Lyr. If you make it a point to observe this variable this month you�ll be able to make a positive observation as it is just beginning to fade from maximum, around 11.2, on its way to the inner sanctum. It spends a lot of time fainter than 14th magnitude, so I always consider it a treat to make a positive observation of a variable so close to M57.

Our next stop is in Draco, the Cat�s Eye Nebula. Located about midway between zeta and delta Draconis, this is another bright planetary nebula on the usual star party agenda. Yes, it�s nice. Take a few moments to soak it in and explain to your guests how planetary nebulae are the remnants of old evolved stars, and then swing about one degree SE and you can show them two such stars in one field, W and X Draconis, one of my favorite �twofers� in the sky. X Dra is located next to an unmistakable triangle of field stars and should just be visible in a 10 or 12-inch around 14th magnitude if you hurry. Like RX Lyr, it spends a good deal of time fainter than 14th magnitude and has a period of 257 days. W Dra ranges from 9-15th magnitude, so it is almost always visible in medium sized scopes. These two are only 14 arc seconds apart, so they are in the same medium to high power field.

From there you can glide into the Milky Way, starting your tour with everyone�s favorite double star, Alberio, beta Cygni. Beta 1 Cyg, the orangish K star of the pair is even suspected of being variable, although I doubt you could do much to prove or disprove this visually. But it is one of those fun facts I like to throw in just to discourage guests from ever coming to a star party at my observatory again! From there it is a relatively easy jump to M56, a globular with a bright core, about 3.75 degrees NW of Alberio, and then almost due east 4.7 degrees is one of the prettiest star fields containing a variable star in the sky. The variable is EM Cyg, a Z Cam star that varies from 11.9 to 14.4, so it is always visible in medium sized telescopes. After you�ve made your estimate you can encourage visitors to slowly slew around the area getting lost in the diamond-clustered field against an ink-black backdrop.

Continuing along the body of  �The Swan� to the NE you�ll come to chi Cygni. With a dramatic range from naked eye visibility (magnitude 3 or 4) to 14th magnitude, this is one of the AAVSO �legacy Miras�; with data going back a hundred years or more. If tat isn�t enough to impress visitors you can track down any number of star clusters, planetary nebulae or diffuse nebulae within a couple degrees of this variable. In fact the area east of chi is a large bright diffuse nebula with the sexy name GN 19.50.2. If that doesn�t impress your guests, slew NW to the �Blinking Nebula� and demonstrate averted vision with the �now you see it, now you don�t� planetary nebulae NGC 6826.

You�ll have to go south again to visit the Dumbbell Nebula, M27. Then you can take a break from the telescope to observe one of the stars in the 10-Star Training Tutorial, eta Aquilae. This is a bright Cepheid observable with binoculars or the naked eye. The observant visitors will want to know what that bright star is in the south, so be prepared to blow your dark adaptation with some glaring views of Jupiter and the Galilean satellites.

By now M31 should be high enough to see with the naked eye from a dark site. You can show visitors where you�re pointing the telescope next while you explain that the Andromeda Galaxy is the furthest thing you can see with the naked eye, some 2.5 million light years away. After you get an eyeful of Andromeda you can swing over to another AAVSO favorite, RX And. This active Z Cam star ranges from 10.3 to 14.0 and it is always doing something. It�s either trying to hide around 14th magnitude, in outburst at 10 or 11 or stuck in a standstill somewhere in-between on any given night.

A little further east and you�ll come to U And, a nice well behaved Mira that varies from 9.9 to 14.4 in 346 days. It�s in a very nice field of stars with a bright triangle of 8th, 9th and 10th magnitude stars to the NE of the variable.

This is a good point to stop. If you really want to squeeze in one more deep sky treat you can slew south to M33 before capping the telescope and calling it a night. Depending on how late it is in the evening or the season, hints of the winter sights to come may be just visible in the east as Orion begins to rise into view. In the next issue, we�ll talk about deep sky treats and variables worth braving the arctic air of a northern winter.

Catching Up

Okay, I'm back! After a rare two week hiatus, we have quite a bit of catching up to do!

While preparing for the AAVSO fall meeting, and then away attending the meeting, I haven't had time to keep you all up to date on what is going on in the variable star and astronomy world that whirls around me each week. So we'll take a few steps back and then plow forward.

October 31, AAVSO announced a special request for observations of 3C 66A, an active galaxy in Andromeda, while it is in its current highly active bright state. I planned to write a blog about this since it is one of my favorite variable objects, and at 2 billion light years, the furthest object I can actually see in my telescope. I hope to write about it this week, but there is a lot of new activity that may take priority over it.

Also just at the end of October the fourth nova in Sagittarius for 2009 was discovered. It is now known as V5584 Sgr. Just yesterday, a new possible nova was discovered in Scutum.

Saturday, November 7, the Slacker Astronomy crew, Michael, Doug and I, aired an episode on 365 Days of Astronomy about the recent, extremely bright, bolide that exploded over Canada, very near our friend Doug's university!

The AAVSO Cataclysmic Variable Section has begun a long-term observing campaign to monitor Z Cam type dwarf novae. I presented the first of what will be several research papers on this at the fall meeting November 7.

I've also started a new web site devoted to Z Cams that I hope will become the authoritative reference on this topic in years to come. I'll be writing more about this exciting project in the weeks to come. This news has not been announced anywhere else except at the AAVSO meeting last weekend, so you readers are getting a scoop here.

Previews of other things coming down the pipe

I interviewed Caroline Moore, the youngest person to discover a supernova, at the fall meeting. She is an incredible young lady. That will be airing as part of a Slacker Astronomy podcast soon.

I have another 365 Days of Astronomy Simostronomy podcast coming up December 7. Its called 'Don't lick the telescope, and other observing tips for winter.'

I received an advance copy of 'The Monthly Sky Guide' by Ian Ridpath and Wil Tirion, so there will be a book review coming soon.

Something notable always seems to happen just around the holidays, a new nova, a rare CV outburst, or something else. What will it be this year? Stay tuned, and we'll find out together.

The Z CamPaign

Introduction
UGZs are defined in the General Catalog of Variable Stars as dwarf novae that �show cyclic outbursts, differing from UGSS variables by the fact that sometimes after an outburst they do not return to the original brightness, but during several cycles retain a magnitude between maximum and minimum. The values of cycles are from 10 to 40 days, while light amplitudes are from 2 to 5 magnitudes in V.�

So it�s all about the standstills, those episodes where the star gets stuck at a mid-point between maximum and minimum. If it doesn�t exhibit standstills it isn�t a Z Cam star.

Typical standstill of Z Camelopardalis

So UGZ can be classified by their light curves alone. Orbital period is not a factor in classification, even though they all tend to be on the long side of the period gap, 3 hours to 10 hours orbital period.
There is no strong agreement between the various CV catalogs as to which few dozen or so stars are actually Z Cam type systems. There are a handful of bright objects that have been densely covered by amateurs throughout their range that are obviously UGZ from their light curves. They show the typical Z Cam-like standstills, have short outburst cycles and amplitudes around 3 or 4 magnitudes.

There are also some bright systems listed as UGZ, like AB Draconis, that have the short cycle and small amplitude, don�t show obvious standstills, and yet it seems everyone agrees they are UGZ.

AB Draconis- where are the standstills?

There are many more CVs that have some of the characteristics of UGZ, but it is not at all apparent from the existing data that they show standstill behavior because the range at which you would expect to see this, somewhere mid-point between maximum and minimum brightness, is too faint for visual observes to have accumulated useful data over the years. All we really know from the data is the average outburst cycle and approximate amplitude. There is no detail in the middle where the real story lies.

Depending on which catalog you use, there are only 30 to 40 Z Cam dwarf novae. If any significant percentage of the number of Z Cams eventually proves not to be Z Cam, the remaining few represent a fairly rare and unique class of stars worthy of further investigation.

Oddballs
Other well-quoted characteristics are that �standstills are always initiated by an outburst,� and �standstills always end with a decline to quiescence� (Hellier, 2001). This may be convenient because it fits the expected behavior, if the models are correct, but there are at least three Z Cam stars that appear to go into outburst from standstill, HX Peg, AH Her and AT Cnc. If this is in fact true, it throws a real monkey wrench into current CV theory.

Hibernation
Another interesting idea is that these Z Cams may be part of a population of �hibernating novae.� According to theory, classical novae systems can evolve into hibernating novae when the secondary star underfills its Roche lobe and mass transfer ceases, possibly centuries after eruption, causing the binary to go into hibernation.

Mass loss during the nova event (or events) results in an increase in orbital separation. The secondary, induced by irradiation of the red dwarf's surface by the white dwarf, continues mass transfer onto the white dwarf. Through this continuous mass loss, the secondary star eventually underfills its Roche lobe and mass transfer ceases.

The shell of ionized gas around Z Cam detected by the Galaxy Evolution Explorer
 is explained as the remnant of a full-blown classical nova explosion.
Credit: NASA/JPL-Caltech/M. Seibert(OCIW)/T. Pyle(SSC)/R. Hurt(SSC)

The binary systems that are most likely to go through hibernation after a nova outburst suffer the largest reduction in mass transfer and increase in separation. In particular, systems with a higher mass ratio are more likely to be induced into hibernation.

The Z CamPaign
The list of stars in the Z CamPaign can be found here.
Stars highlighted in yellow are stars that are confirmed UGZ suitable for continued observation by visual observers throughout their cycles. We strongly urge visual observers to continue monitoring these stars for their expected outbursts and standstills.
Stars highlighted in green are stars that visual observers should continue to monitor for outbursts and standstills if or when they may occur.
Stars with no highlights are stars which both visual and CCD observers are encouraged to monitor for outbursts, but the standstills are likely to only be visible to CCD observers due to their relative faintness (15th or 16th magnitude).
Stars highlighted in blue are best suited to CCD observers for monitoring for outbursts and standstill behavior.
Stars highlighted in red are those which appear to go into outburst from standstill. When one of these stars enters a standstill we will be asking for intensive coverage until the star either goes into quiescence or outburst.
We will devote a special place on the home page for notifications and reminders of current Z Cam and suspected Z Cam activity, the Z Cam Corner.
We also plan to build a website devoted to Z Cam and suspected Z Cam stars, with pages for individual stars, finder charts, data tables and links to relevant literature, along the lines of The Big List of SW Sextantis Stars (D. W. Hoard) and Intermediate Polar Home Page (Koji Mukai).

Science Goals
1. To determine convincingly which CVs are indeed UGZ and which are imposters.
2. To improve the overall data available on each of these stars and fill the gaps in the light curves.
3. To determine if some UGZ actually do go into outburst from standstill, or if perhaps we have just missed the sudden drop to quiescence before the next outburst, leading to the appearance of outburst from standstill behavior.
4. To make any other serendipitous discoveries about 'UGZ-ness' that come to light as a result of improved coverage.
5. To publish the results in a peer-reviewed journal such as the Journal of the AAVSO.
Z Cam stars are not the sexy, super-humping members of the CV family. In fact, they are rather ignored for the most part by amateur and professional alike. Perhaps because it is easier to make a classification of a UGSU from only a few nights observations of superhumps, or because the reason for standstills to occur is not well-understood. This leaves the door open for discovery to those patient and persistent enough to devote time and energy to observing this unique class of cataclysmic variable. We hope you will join us in this endeavor.

The Sky Is Falling, the Sky Is Falling!

Meteor watching doesn�t require any special equipment at all, but is best enjoyed when the moon is out of the way. Fortunately, this year�s Leonid meteor shower peaks November 17, right around New Moon. If the sky is clear, you could be in for a treat.

Leonid meteors start out as specks of dust and debris ejected by Comet 55P/Tempel-Tuttle, which orbits the Sun every 33 years. Over time, these particles spread out along the comet's orbit. Every November, Earth passes through this stream of cosmic debris.

These particles hit our atmosphere at 147,000 mph and vaporize in the upper atmosphere from friction with the air. This produces the streaks of light in the sky we call meteors. Leonids are swift, dashing meteors that often have flares at the end of their trails. Some of them leave behind persistent trains, like tiny vapor trails from jets.

By the way, when these particles are flying through space they are known as meteoroids. If they survive the fiery ride through the atmosphere and hit the ground they are called meteorites.

This meteor shower is called the Leonids because if you trace all the shower's meteor paths backward, they appear to radiate from a point in the constellation Leo the Lion. This point of origin is known as the radiant. The Leonids radiant is very near Gamma Leonis.

Observers are normally rewarded with 20 to 30 meteors per hour, but the Leonids have surprised us in the past. In 1833 the Leonids shower was actually a meteor storm, with a hundred thousand meteors per hour putting on a show. In 1966 observers in the US saw Leonids falling from the sky like rain, at a rate of thousands per minute. In 1998, the year of Comet Tempel-Tuttle�s last return to the inner solar system, there was a brilliant display.

The peak of activity coincides with when the Earth passes through the thickest part of the debris trail left behind by Tempel-Tuttle. Predicting just when that will happen is difficult, but predictions seem to get more accurate each year. If you�re lucky you could see hundreds of meteors. If not, the few dozen you see will be reward enough for some time well spent under the stars.

I�m willing to go out on a limb and make a prediction. If you don�t go outside and look up in the next few days, you won�t see any meteors.

Pria Gemuk Tergeletak Di bawah Lantai

 

Kananpapan,Sulangtesi 34/34/3434, CrapNews - Seorang pria gemuk ditemukan tergeletak dibawah lantainya saat polisi memeriksa, rupanya pria gemuk itu kekenyangan, pria gemuk itu dibawa ke we se untuk pengeluaran barang dari fanthatnya itu.

Diduga pria itu memakan makanan yang bisa membuat kenyang. Jadi, kita harus hati hati dalam memilih makanan. Sebab, bisa menyebabkan kekenyangan dan jika kita tidak kekenyangan pasti kita tidak kekenyangan *mulai ngawur

Sebelum kejadian itu, juga ditemukan seseorang yang kelaparan. Ia mati diduga karena kurang makan dan kurang kenyang

Wartawan : Fahrezano Bayuno Pradiptano

(hebat/crapnews)