Affiliation
American Association of Variable Star Observers (AAVSO)
Sat, 07/02/2016 - 08:06
Hi All
Just to let you know that the LPV section web page has recently been updated. This includes a new LPV of the Month for July which is the interesting star T UMi. Thanks for Frank Schorr for putting this together.
If anyone would like to contribute a brief article on their favourite LPV, then we would be very keen to hear from you!
Enjoy the page and if there's anything in particular you'd like to see on it, please contact us.
Regards
Andrew Pearce (PEX)
Thank you to all involved in updating the LPV observing section - great job! I can't wait to see more contributions to the "LPV of the month" page - and I would like to invite you all to write a paragraph about your favorite star. This is a great way for our community to learn from eachother's experience!
Best wishes - clear skies,
Stella.
Thank you for doing this! As you may know, my students and I have been busy analyzing data on stars in the AAVSO LPV observing programs. Almost all of this is published in JAAVSO. See, for instance: volume 44, 72; 43, 223; 43, 118; 42, 245; 42, 1; 41, 193; 41, 1; 41, 15; 39, 1; 38, 161; 37, 71. I particularly recommend 41, 193 by Percy & Abachi which reports an exciting (to me) new discovery about LPVs. Also 39, 1 by Percy & Terziev which suggests many stars on the program which should or should not be observed. This summer, Henry Leung and I are looking at two samples of LPVs: the ones on the AAVSO PEP program, and the ones on the binocular program. All this is made possible by the work of AAVSO observers! Stay tuned for our results!
John Percy
I would be especially interested in your findings on the binocular observing program stars. I am a frequent binocular observer. I often wonder if some of the targets on the list are really worth observing, given their narrow range of variation and scatter in the light curves (although I imagine some light curve analysis may reveal some periodicity/regularity even from these binocular observations). If you are looking for help, I would be willing to take on some analysis assignments on cloudy nights!
My student Henry Leung is still working on the binocular stars. Even though they seem to have small amplitudes, and scatter in the light curve, they still produce excellent results, thanks to the "black art" of time-series analysis. We detect pulsation periods and, in about a third of the stars, "long secondary periods" whose nature is stilll not known. We can detect amplitudes of a few hundredths of a magnitude in these stars. So keep up the good observations!
As Henry is working on the binocular stars, I am studying the LPVs which Janet Mattei and I placed on the PEP program, back in the 1980's, because their amplitudes were rather small. For these,, we have both visual and V data, and we are able to detect amplitudes down to 0.03 mag. We should be writing this up for JAAVSO by September.
John Percy
I started observing variable stars in 2015 using binoculars. Your articles (Percy) have been helpful in determing which stars to include in my observing program. In particular your series ending in, JAAVSO, Vol. 39, 1 (Percy & Terziev) has shown me that certain variables are appropriate for continued observations and certain variables do not need continued observations. I appreciate that information and have included "Higher Priority" variables from Table 2 such as VY UMA, PSI 1 AUR, and AT DRA in my program. All of the variables that are included in my program come from the PEP and/or Binocular Program Lists and I appreciate your (Percy) efforts in developing one or both of these lists. I look forward to your continued studies of variables from these AAVSO program lists and hope that consideration can be given to updating these lists based on your past and future recommendations.
Rich GRIB
Keep in mind that "higher priority" is relative. The lower-priority stars -- non-variable and microvariable -- are definitely low priority, especially for visual observing. But even the higher-priority stars will be a bit of a challenge, since they are classified as irregular (L type). But keep up the observations, and I will try to reanalyze them in a year or two.
John Percy
Hi All
We've included a new LPV of the Month article on the web page. The LPV for August is RS Eri and we hope you find the article interesting. If anyone would like to write a brief story on their favourite LPV, we'd very much like to hear from you.
Regards
Andrew Pearce
Hi All
Frank Schorr has written an interesting piece this month on LX Cyg. This is an LPV which has displayed pronounced changes in it's period in a relatively short space of time. I'd encourage you to read the article and consider adding this interesting star to your observing program.
If anyone would like to contribute a brief article on their favourite LPV, we'd be very happy to hear from you.
Regards
Andrew Pearce (PEX)
Hi Andrew, I spelt your name wrong in AS&T. Appologies! A bad mistake.
Best...
Hi All
Just to let you know that the LPV web page has recently been updated. As well as a new LPV of the month (S Cep), thanks to Frank Schorr, we also have a very good article from Dr John Percy on why we should be observing LPV's. John is a science advisor to the LPV section and we greatly appreciate his support. I encourage you all to read John's piece which will hopefully encourage more observers to take up LPV observing! Also we reference a very good article on forgotten Miras by members of the Variable Star Section of the Association of Swedish Amateur Astronomers (SAAF/V) which appears in the current edition of the JAAVSO.
Enjoy!
Andrew
Hi All
Just to let you know that the LPV web page has recently been updated. As well as a new LPV of the month (TT Cen), we have set up a new page entitled "Why observe LPV's?" based on the article provided by John Percy last month. We also plan to revisit the LPV Legacy and Program stars lists which were first put together about 7-8 years ago. This may include the addition of a few more stars. Currently there's not many southen LPV's included and provided we confirm that some of these southen LPV's have a significant observational history and some professional interest, we may look at including them formally on the lists.
Regards
Andrew
Hi All
Just to let you know that the LPV section web page has recently been updated. This includes a new LPV of the Month for December which is the interesting star R Aur.
If anyone would like to contribute a brief article on their favourite LPV, then we would be very keen to hear from you!
Regards
Andrew
Hello Andrew,
very good and interresting article.
Regards, Hubert
Thanks Hubert
The feedback is appreciated. The page has been recently updated and the LPV for the month of January is RS Cyg. Check it out!
Regards
Andrew
Hi All
Just to let you know that there has been an update of the LPV Section web page. The LPV of the month is U UMi.
During January, I completed work on reviewing the LPV Legacy stars list. This was originally developed back in 2009 by Mike Simonsen and Kate Hutton. They did a great job in identifying important LPV's to follow to ensure that we continue the long observational history of these stars and they reflect the long tradition of the AAVSO.
Using the same 2009 criteria developed by Mike and Kate for defining the Legacy list, I have identified a further 21 stars which have been added to the Legacy list.
The current list of AAVSO Legacy Stars can be found in our file section (the file is titled "AAVSO Legacy LPVs 2017 Update").
The vast majority of LPV's in the legacy list are north of the celestial equator which is understandable given most observers have been located in the northern hemisphere. However to ensure there is sufficient coverage south of the celestial equator, a separate legacy list has been developed for LPV's south of declination 20S (southern stars in the existing liegacy list will remain there, so this new list just contains additional stars). The selection criteria as first proposed by Mike and Kate remains, however it is necessary to relax the criteria somewhat. All stars on this southern list have been under observations since before 1950, have over 5,000 observations in the AID and have been referenced in over 50 scientific publications over the years. This resulted in a list of approximately 30 stars and again is a subset of the original Pickering program list.
The current list of AAVSO Legacy Stars South can be found in our file section (the file is titled "AAVSO Legacy South").
It should also be noted that the LPV Legacy star list and LPV Legacy South list can all be searched in VSX under "Campaign or Program".
As always, we're happy to receive any feedback as to what observers would like to see on the web page.
Regards
Andrew
Thanks Andrew. I do a handfull of these already. I'll try and do those better before taking any new ones on.
Best. Alan.
Hi All
The web page has been updated again. The LPV of the Month for March is R Lep.
One of the LPV Section Science Advisors and JAAVSO Editor, Dr John Percy, has put together a list of pulsating red giants that have and continue to show interesting and/or unusual behaviour. We would like to promote the stars that appear on John's list as worthy of intense coverage for all observers, visual observers in particular. The list includes many stars which are currently on the LPV Legacy and Legacy South lists as well (highlighted in yellow in the file). The March LPV of the Month, R Lep, appears on John's list.
The list has been designated "The Percy List" and can be found in our file section (the file is titled "The Percy List.pdf").
Enjoy!
Regards
Andrew
Hi Andrew, thanks for the update. Just 1 comment: the link to the LPV forum in the text does not work
Thanks for letting us know about the link to the LPV forum, Hubert. It's fixed and working now.
Good observing,
Elizabeth
Hi All
Just to let you know that the LPV Section web page has been updated and the LPV of the Month for April is V Hya. This article was provided by Mike Soukup which we greatly appreciate. I hope this generates some interest in more detailed coverage of this fascinating LPV.
Regards
Andrew (PEX)
Hi Andrew,
very interesting article. It looks indeed a fascinating LPV. Sadly to low from my observing place.
Hi All
Just to let you know that the LPV Section web page has been updated and the LPV of the Month for May is R Hya. This article was provided by Frank Schorr and is an interesting read on a fascinating LPV.
Regards
Andrew
Hi All
Just to let you know that the LPV Section web page has been updated and the LPV of the Month for June is BH Cru. This article was provided by Frank Schorr and is an interesting read on an LPV with a short observational history but one that has shown appreciable changes in it's behaviour.
Regards
Andrew
Hi All
Just to let you know that the LPV Section web page has been updated and the LPV of the Month for July is T Cas. This is an interesting northern sky LPV which displays a double maximum feature in it's light curve and there are not many of these types in the northern sky.
Regards
Andrew
Hi All
Just to let you know that the LPV Section web page has been updated and the LPV of the Month for August is CT Lac. Thanks to Frank Schorr for putting together an interesting artcile on this star.
Regards
Andrew
Nice article. I never observed this star but is seems worth to do it.
Clear skies.
Hi All
The web page has been updated and the LPV for the Month for September is T Cam.
Also just to let you know that Alredo Glez-Herrera (GZN) has established a Facebook Long Period Variable group. So far there's over 80 members of the group and will be a great way to provide more "immediate" news and views on all things LPV. I'd encourage you to search and join the group if you have an interest in these fascinating stars.
Regards
Andrew
Hi All
just to let everyone to know that the LPV of the month for October is R Aql. An interesting article has been supplied by Frank Schorr. Thanks Frank!
Do you have a favourite LPV? Do you fancy sharing your interest with the AAVSO community? A brief article is an excellent way to do this and doesn't require a physics or astronomy degree! As you can see from other monthly articles, the focus is on the observational history of the stars and leveraging off the AID dataset. I'd be happy to receive any articles from any member and observer.
Regards
Andrew
Hi All
Just to let everyone to know that the LPV of the month for November is R Cnc. R Cnc is an interesting LPV which has shown a marked decrease in it's mean magnitude over the last 50 years or so and from my research, I can't find a very good explanation for this!
Again, I'd be happy to receive any articles from any member and observer on your favourite LPV.
Regards
Andrew
Hi All
The article on R Cnc has been updated to reflect some great comments received from Stan Walker of the VSS. Stan pointed out the pitfalls of analysing LPV's such as R Cnc with periods close to a calendar year. Thanks Stan!
Regards
Andrew
Hi All
just to let everyone to know that the LPV of the month for December is RU Vir. An interesting article has been supplied by Frank Schorr. Thanks Frank! I encourage observers to monitor RU Vir in it's upcoming observing season.
Do you have a favourite LPV? Do you fancy sharing your interest with the AAVSO community? A brief article is an excellent way to do this and doesn't require a physics or astronomy degree! As you can see from other monthly articles, the focus is on the observational history of the stars and leveraging off the AID dataset. I'd be happy to receive any articles from any member and observer.
Regards
Andrew
Hi All
Just to let everyone to know that the LPV of the month for January is Khi Cyg. An interesting article has been supplied by Alfredo Glez-Herrera. Thanks Alfredo! It's a Mira with a very long observational history which still surprises. Check out the LPV Section web page for other recent updates.
Regards
Andrew
Hi All
Just to let everyone to know that the LPV of the month for February is Z Tau which follows on from a recent series of posts to the Forum regarding the difficulties when oberving the star when faint due to a close companion star. It's a Mira with interesting long term changes in it's mean period. Check out the LPV Section web page for other recent updates.
Regards
Andrew
Thanks to Andrew and Frank and others who show us their interests and enthusiasm each month with the articles on long period variables. As a newer observer, I learn much from these stories. These articles continue the Variable Star of the Season tradition of showing us the observational history of single pulsating variables including references to other articles that supplement the information on the variable.
Thanks also to Andrew and other AAVSO members who write similar articles each month in the Variable Stars South Newsletter. For example, the current VSS 2018-1 newsletter contains several articles on single pulsating variables written by AAVSO members including Andrew along with articles on other types of variable stars.
I plan on continuing my observing of binocular variables and hope that sometime in the future I will feel like I can contribute information on a favorite variable. Thanks again to everyone for their efforts in sharing with us the variables that interest them.
Rich GRIB
Hi Rich,
I'm glad you enjoyed the articles in the latest Variable Stars South newsletter. For anyone else who may be interested all our PDF newsletter issues are freely available for download from our website. Most VSS observing projects are southern hemisphere oriented but northern observers will find much of interest too. Cheers,
Mark Blackford
Director, Variable Stars South
Hi All
Just to let everyone to know that the LPV of the month for March is V Bootis. It's a semi-regular with interesting long term changes in it's amplitude. Check out the LPV Section web page for other recent updates.
Regards
Andrew
Hi All
The LPV of the month for April is S Cas. It's a Mira with interesting long term changes in brightness as well as humps in the light curve. Check out the LPV Section web page for other recent updates.
Regards
Andrew
Hi All
The LPV of the month for June is R Nor. It's a southern Mira with the rather rare habit of displaying double maxima in it's light curve. Check out the LPV Section web page for other recent updates.
Regards
Hi All
The LPV of the Month page has been updated and the star for July is SS Vir. It's a bright red carbon star and displays interesting long term characteristics in its light curve. Thanks to Frank Schorr for putting together a very interesting article.
Regards
Andrew
Hi All
The LPV of the Month page has been updated and the star for September is S Aur. It's a red carbon star and displays interesting long term characteristics in its light curve. Thanks to Frank Schorr for the article.
Regards
Andrew
Hi All
The LPV for this month is actuallya bunch of Miras all from the same constellation of Columba. Enjoy!
Another imporant addition to the LPV Section site is an article by Stan Walker (until recently Stan was the Director of Variable Stars South) on the changing scene of LPV observing. In particular Stan discusses PEP/CCD observations of Miras and provides important guidance on what can be done which follows on nicel from some recent forum posts on a similar topic. Thanks very much to Stan for putting this together. The article will remain accessible at all times on the web page and can be found here.
Regards
Andrew
Hi All
The LPV of the Month page has been updated and this month we're looking at the very interesting carbon star, S Ori. This article was written by Frank Schorr, so thanks Frank!
We plan to reduce the frequency of the LPV of the Month series in 2019 down to quarterly as unfortunately there hasn't been too many offers from members and observers to write about their favourite LPV.
Regards
Andrew
Hi All
The LPV of the Season page has been updated and this month we're considering an RV Tau star, DF Cyg. This article was prepared by Rich Roberts. Thanks Rich! The LPV Section has sort of taken RV Tau under it's wing! The article can be found here.
Regards
Andrew