OJ+287 update

We have just had a communication from Dr. Mauri Valtonen. He
advises me that he has just received new data from USA observers,
which has improved the start date for the 2005 outburst (brought
it forward by two weeks). This has now resulted in a revised
date for the 2007 outburst - September 5th +/- 3 days.
Unfortunately this takes us closer to Solar Conjunction than
before, and will be a challenge so close to Sunrise.
It is however vital that we follow OJ into conjunction as late
as possible, and make every attempt to detect it in the morning
sky as early in September as we can.

Regards

Gary Poyner and the 200,000th....

Congratulations to Gary Poyner on reaching his 200,000th recorded VS visual observation, I was astounded by this figure (I think only 3 other people have achieved this) and it is a remarkable testament to his dedication and contribution to the astronomy world. In addition to all this he has achieved it from the light polluted skies of central Birmingham.
On a personnel note having met him on a few occasions he is a great communicator on the subject and will always find the time to assist and advise people like myself.

Regards

A fair bit of catching up to do.

I have started a new work contract last week, and leaving home at 6.30 returning home at 7.00pm has not left me much time for all the important VS things. Will catch up with all the info and report back

Regards

OK we are 64bit ready etc.

All updates done and successful, posts will start to appear tonight.

Regards

For a few days there will be no posts....

Sorry about this but at the weekend some essential PC and Laptop upgrades must be actioned etc...
I apologise in advance and hope all being well service will resume on Monday 16th April 2007.

Pigott and Goodricke

Well, with the best intentions I started to write a small essay on the above gentlemen, but soon discovered that it was impossible to gather a piece about them without typing reams of material. I first heard about them at a BAA "Winchester Weekend" lecture and have been interested since. If you consider the period of the astronomy lifespan that they studied in (1764 - 1825) and the quality of equipment they would have used, and then on top of that the fact that they could communicate in writing only, it makes these two astronomers real history makers of the Variable Star world.
Please follow the links and read other articles on the web that you can find on them, it is an interesting journey of adversity and triumph.
Probably over done it with the emotions there but.......

http://en.wikipedia.org/wiki/Edward_Pigott

http://en.wikipedia.org/wiki/John_Goodricke

BAA and AAVSO Mentor Schemes....

Both the British Astronomical Association and the American Association of Variable Star Observers run "Mentor Schemes", where by contacting the relevant orgs they get in touch with an agreed observer to assist you in starting out in your career as a Variable Star Observer.
On the BAA side it will be Roger Pickard and with the AAVSO Mike Simonsen. Please do not hesitate to contact them via the relevant websites, or myself in case of difficulty of contacting the aforementioned gentlemen. Variable Star observing is the one area where amateurs continue (and will do so for decades to come)to contribute to the professional arena. I will post a separate item on the reasons behind this tomorrow.
Might even get the Goodricke / Pigott piece done over the Easter break.

Regards

AAVSO publishes its VS of the Season

OK, I was reading my daily AAVSOnews feed (sad aren't I ) and saw this. I have unashamedly lifted it complete, (please contact my solicitor with any copyright issues) but thought this interesting enough to post here.

RU Virginis
The Mira variables undergo some of the most dramatic behavior among all of the variable stars. For just that reason, they were among the earliest variable stars discovered and followed by astronomers trying to understand how our universe works. Four centuries after their discovery, the Mira variables remain one of the most challenging variable star classes to understand. All Miras are "dying stars", soon to shed most of their mass, leaving only a white dwarf behind. To fully understand these objects, we have to understand late stellar evolution, the physics of high-amplitude pulsations and convection, mass loss and stellar winds, and all of the microphysics and chemistry that ties them all together. Individual Mira stars are themselves in transition, but they also represent another cosmic transition in progress. Because the Mira stars are in the stage of their evolution during which most of their mass is returned to the galaxy through stellar winds and mass loss, they are a key mechanism for cosmic chemical enrichment for new generations of stars. Our understanding of how our galaxy and the larger universe are evolving depends in part upon the study of Mira variables.

Visual magnitude estimates (25-day averages) of RU Virginis from theAAVSO International Database.
No two light curves look alike -- Miras light curves are really like snowflakes. And a few Miras have truly remarkable light curves, with lots of interesting behaviors going on at the same time. This quarter brings into view one of these curious Miras -- RU Virginis. RU Vir is one of many Miras in the AAVSO observing program whose light curve has hit the century mark, and more (and more varied) observations continue to be made. RU Vir has shown some perplexing behavior ever since its discovery, and this behavior may help to shed light on some fundamental physics of stars at the ends of their lives. This makes RU Virginis a deserving target of our Variable Star of the Season series.
A short history of RU Virginis
The recorded history of RU Vir dates to the late 19th Century, and the cartographic work then being done at the Dudley Observatory in Albany, New York. At the time, Dudley was under the directorship of Lewis Boss, compiler of the Preliminary General Catalogue of 6188 stars -- the first Boss Catalog -- and also the uncle of the AAVSO PEP pioneer Lewis J. Boss. The Boss catalogue was meant to be a more accurate and complete astrometric and proper motion survey than had been done before. Proper motion surveys require multiple observations of the same regions of sky many years apart, and so it's no surprise that such a survey might uncover some long period variable stars.
Leon Campbell with the AAVSO at HCO, 1915.In 1897, Arthur J. Roy, a staff astronomer of the Dudley Observatory, published a note on a star in Virgo found during observations for the Boss Catalogue that did not appear in the Bonner Durchmusterung published half a century earlier. Roy gave several magnitude estimates made between May 1895 and March 1897, and also noted that it was a very red star. Although he gave no suggestion as to the type of variable, a light curve of Roy's magnitude estimates could easily match that of a Mira. After Roy's discovery, several observers -- including early amateur observers Seth Chandler Jr. and Henry Parkhurst -- began recording the light curve of RU Vir, and it entered the AAVSO's published light curves with Leon Campbell's first observations in 1904, published in Harvard Annals.
The light curve of RU Vir began to show curious behavior almost immediately with a pronounced declining trend in average magnitude. Later photometric studies confirmed and clarified the red spectral type of this object, and by 1940 it was a known carbon star -- a star with pronounced spectral absorption features of carbon. By the end of the 20th Century, the long-term light variations of RU Vir proved to be cyclical, and the nature of this and similar stars were under intense scrutiny by the astronomical community. RU Vir and asymptotic giant branch (AGB) stars like it remain an interesting astrophysical puzzle, and theoretical studies of these stars continue.



Regards

Internet speeds...off subject.

I think I was asked twice at the Winchester Weekend about problems with download speeds.
For those that think they have problems use this link http://www.speedtest.net/
it is self explanatory and is a good guide.

Regards

OJ+287 now is the time.

OJ+287 is reaching quite a crucial time against its outburst prediction models. There have been many attempts to predict its behaviour but none have really got close. Now as we come up to the summer months Dr Mark Kidger has posted the following comments on the BAAVSS alert page.

BAA-VSS members will know that observing OJ287 over the next few monthspresents a unique opportunity to check different professional modelsthat have attempted to explain the long-term light curve. Monitoring todate by the BAA-VSS has tied down the models tightly to the point wherethe predictions are now just about definitive and more data will give adefinite yes/no. Already BAA-VSS data can rule out completely one ofthe alternative binary black hole models that has been proposed. Themodel from Mauri Valtonen, using BAA data from 2005/06 now makes aquite definitive prediction that there should be a new outburst thatpeaks on September 16th, with an uncertainty of no more than a coupleof days in the date of maximum.At the moment the quasar is very active and the base level seems to berising in the expected way for an imminent outburst. However, if we areto nail the model and either confirm it or reject it beyond allpossible doubt, it is essential to make the greatest effort to coverthe light curve over the next few months. This means following OJ287down into twilight in June as late as possible and ensuring that it isrecovered in twilight as early as possible in September because, if themodel is correct, by the end of the first week of September, whenobservations should be just possible at dawn, OJ287 should already bealmost at maximum.It is absolutely critical to close the gap at conjunction as much aspossible to avoid the light curve being clouded by the same "what didwe miss" doubts as in 1995 where it is suspected that the outburst fellexactly at conjunction and only the earliest stages of the rise werepicked up. This time the theoreticians will have no escape if theobservations do not agree with the models!

..............................................................................................
From my own thoughts:
Now I had OJ+287 down as a blazar where as Mark relates to it as a quasar, but it seems they have ruled out the binary black hole (blazar) due to results and predictions not being met.

I will post more on this early next week when I discover more.

Regards

CV's from the Hamburg Quasar Survey...

Here is the link (as promised in an earlier posting) for the Boris Gaensicke project concerning the above items.
http://deneb.astro.warwick.ac.uk/phsdaj/HQS_Public/HQS_Public.html

Any observations of these are most welcome and can be reported to Gary Poyner (see VS Links) and are rated in importance at the bottom of the link page above.

Regards

Z Cam not such a rumour.....

As reported earlier here is a quote from the GALEX site which explains what they have discovered.


GALEX FINDS LINK BETWEEN BIG AND SMALL STELLAR BLASTS
Full text:
GALEX-2007-01
GALEX FINDS LINK BETWEEN BIG AND SMALL STELLAR BLASTS
Proof that certain double star systems can erupt in full-blown explosions and then continue to flare up with smaller bursts has been spotted by the ultraviolet eyes of NASA's Galaxy Evolution Explorer.
The finding bolsters a 20-year-old theory that suggests such double-star, or binary systems, should eventually undergo both types of explosion, rather than just one or the other. It implies the systems probably cycle between two blast types, hiccupping every few weeks with small surges until the next giant outburst about 10,000 years later.
"The new images are the strongest evidence yet in favor of the cyclic evolution of these binary stars," said Dr. Mike Shara of the American Museum of Natural History, New York, lead author of a new paper that details the finding in the March 8 issue of the journal Nature. "It's gratifying to see such strong evidence for this theory finally emerge after all this time."
The new discovery centers around Z Camelopardalis (Z Cam), a stellar system that astronomers have long known to be a cataclysmic binary -- a system featuring a collapsed, dead star, or white dwarf, which behaves like a vampire sucking hydrogen-rich matter from a companion star. The stolen material forms a rotating disk of gas and dust around the white dwarf.
Astronomers divide cataclysmic binaries into two classes -- dwarf novae, which erupt in smaller, "hiccup-like" blasts, and classical novae, which undergo huge explosions. Classical novae explosions are 10,000 to a million times brighter than those of dwarf novae, and they leave behind large shells of shocked gas.
About 530 light years from Earth, Z Cam was one of the first dwarf novae ever detected. For decades, observers have watched the system hiccup with regular outbursts. It brightens about 40-fold every 3 weeks or so, when an instability causes some of the material drawn by the stellar vampire to crash onto the white dwarf's surface.
Theory holds that Z Cam and other recurring dwarf novae should eventually accumulate enough matter and pressure from their swirling disks of hydrogen to trigger gigantic hydrogen bombs - classical novae explosions. But no one had found definitive evidence that a binary had experienced both types of blasts until the Galaxy Evolution Explorer's observations of Z Cam, which began in 2003.
That's when Dr. Mark Seibert of the Carnegie Institution of Washington in Pasadena, Calif., serendipitously noticed a never-before-seen arc and linear features surrounding Z Cam in imaging data the Galaxy Evolution Explorer collected during its Survey of Nearby Galaxies. The features indicated the presence of a massive shell around Z Cam -- evidence that the dwarf nova had in fact undergone a classical nova explosion a few thousand years ago.
Previous observations had failed to reveal the massive shell because it cannot be easily detected at optical wavelengths. It is, however, easily seen at the ultraviolet wavelengths detected by the Galaxy Evolution Explorer.
"You could actually see it immediately," Seibert said. "But we had to convince ourselves that we were really seeing a nova remnant."
Narrowband images from Kitt Peak National Observatory near Tucson, Ariz., Palomar Observatory near San Diego, Calif., and the Wise Observatory near Mizpe Ramon, Israel, along with optical spectroscopic measurements made at the Lick Observatory near San Jose, Calif., by other team members confirmed that the structures detected in the Galaxy Evolution Explorer imaging data were indeed a massive shell of gas surrounding Z Cam.
The authors of the new paper write that Z Cam's classical nova explosion must have been quite spectacular. "During that eruption," they write, "it must have become, for a few days or weeks, one of the brightest stars in the sky."
Images of Z Cam from GALEX, an artist's concept animation of Z Cam, and additional information about Galaxy Evolution Explorer is online at http://www.galex.caltech.edu.


Regards

Winchester Weekend...

Well met up with Gary Poyner, Jeremy Shears, Roger Pickard,Guy Hurst, Karen Holland etc etc, and a bunch of reprobates from the Heart of England Astronomical Society. To say they made the weekend would be an understatement. Apart from the laughs, and that didn't stop all day, it would be hard to find a more knowledgeable and friendly bunch of people willing to impart advice . To all of them a big thank you.

Regards

P.S. A more serious report to follow.

Z Cam and a rumour.....

Rumours, the GALEX (Galaxy Evolution Explorer) team in the USA has reportedly put in a research paper that explains that Z Cam is not what it was thought to be, a dwarf nova-type cataclysmic variable. It is now thought to be of a completely different class. This will create a knock on if true, to a whole class of variable stars being looked at and researched again.

More on this later as I gather some facts today.

Regards