LPV'ers,
The LPV program was established in order to concentrate visual observers on high value targets with long observational histories. Since we have long histories on these stars, we can monitor for long-term evolutionary changes. It will be a long time before we have similar photometric histories from surveys to do this work.
We need visual observers to continue to work these program stars.
I've been looking at the number of unique visual observers and total visual observations of program stars from 2016 to 2020 and the trends are not good.
Unique visual observations are down 23% from 2016 and visual observations are down 19%.
While some program stars are still being well observed and even trending upwards, I found that 197 out of the 388 program stars saw large dips (>10%) in observations relative to their 5 year average.
I'm going to keep drilling down on my lists and will highlight specific stars which require more attention. So keep a look out!
As always, the LPV program should be the cornerstone of your visual observation program. A spreadsheet of the program can be found on the LPV section webpage and is searchable in VSX.
Let's give these stars the love and attention they deserve!
Clear Skies,
Rich (RRIA)
Rich:
Sorry for this LPV beginner question, but I'm confused about "the LPV program". I find three lists referenced from the LPV Section Home Page:
Is there a difference between a "legacy star" and a "program star"? Does one of these lists supersede another by virtue of date? Or are there three distinct categories of LPV stars within the AAVSO program, each with its own priorities and observing objectives?
Thanks in advance,
- Mark M
Good question!
…
Hi Mark,
Good question!
The LPV program has been the cornerstone of LPV observing for many decades. These are stars with long observations histories which the AAVSO wants visual observers to monitor.
Since there are so many stars in the LPV program, many years ago one of my predecessors came up with a criteria to identify the most important (mainly most often observed) of these stars and created the Legacy LPV list. The list was again updated by a different predecessor in 2017.
So the Legacy Star list is a subset of the LPV program.
One way to look at it, the LPV program stars are the important stars and the Legacy LPVs are the really, really important stars in the LPV program.
The target tool contains stars from various sources, most notably from observing campaigns. For example, a researcher requested AAVSO monitoring of several LPVs because he was studying LPV MASERs. He provided a list of stars and they all went into the target tool.
The target tool also contains all the LPV Legacy stars, so there is certainly a lot of overlap.
On a personal note, I tend to gravitate more to the LPV program stars which are not also Legacy stars. The Legacy Stars tend to be very bright and very well observed. I feel I can for more good going for LPV program stars which are not getting as much attention.
I will star posting more about such stars shortly.
Clear Skies,
Rich
Ah... that clarifies things. And this is actually a well-timed discussion. I concentrate on BVRI photometry of LPV stars, and recently upgraded my camera (from an SBIG ST-9 to a QHY268M). The new camera requires significantly shorter exposure times (and faster download times), which is enabling me to expand my observing list. There are several different possibilities:
I guess my takeaway from all this is that I'll see what else I can harvest from the northern objects in the LPV program star list that are currently either under-observed in general or that are splotchy in B, Rc, and/or Ic as I move to keep the new camera busy.
- Mark M
Here are 42 program stars currently well positioned in the sky which have seen >20% drops in visual observations of the past 5 years. please give them love. AH Dra
BO Mus
R Cam
R Cen
R Com
R Hya
R Nor
R Sco
R Vir
RR Boo
RR CrB
RR Sco
RS Lib
RS UMa
RU Vir
RV Cen
RX Boo
RX Cen
RY Dra
RZ Sco
S Boo
S CrB
SS Oph
SW CrB
T Aps
T Cen
T CVn
T Nor
TT CrB
U Boo
U Cen
U Oct
U Ser
U Vir
V CrB
V CVn
V Oph
X Her
Y UMa
Z Boo
Z CrB
Z Sco
AH Dra
BO Mus
R Cam
R Cen
R Com
R Hya
R Nor
R Sco
R Vir
RR Boo
RR CrB
RR Sco
RS Lib
RS UMa
RU Vir
RV Cen
RX Boo
RX Cen
RY Dra
RZ Sco
S Boo
S CrB
SS Oph
SW CrB
T Aps
T Cen
T CVn
T Nor
TT CrB
U Boo
U Cen
U Oct
U Ser
U Vir
V CrB
V CVn
V Oph
X Her
Y UMa
Z Boo
Z CrB
Z Sco
Here is a list of stars from my under-observed LPV program list which are currently well positioned in the sky. Please observe them!
S CrB
S Lib
RS Lib
R Nor
SW CrB
RR CrB
T Nor
TT CrB
Z CrB
Z Sco
U Ser
W CrB
R Sco
S Sco
V Oph
SS Her
RS Sco
SS Oph
RV Her
SY Her
R Oph
RT Her
RS Her
U Ara
T Dra
V Dra
RY Her
X Dra
TV Her
TU Lyr
SV Her
RV Sgr
RY Lyr
S Sct
RX Lyr
U Dra
TZ Cyg
R Sgr
AV Cyg
UX Dra
AW Cyg
TU Cyg
T Pav
S Pav
RU Sgr
The list of LPV Legacy stars published some years ago, included close to 350 variables, but now I cannot found this legacy list and the target list shown in the web is much shorter. Several of my favourite stars dropped like ST SGR.
Is this true?. Has been really reduced the number of LPV stars of the legacy list that require observations?.
Should we eliminate from our list the stars monitored so far that do not appear in the Target List ?.
Thnak you i advance and best regards.
PUJ
Here is a detailed explanation of the LPV Program and LPV Legacy Stars. https://www.aavso.org/aavso-legacy-lpv-program
In summary, the LPV program contains 388 we recommend for continued observation. A spreadsheet containing all the program stars is on the LPV section website. https://www.aavso.org/lpv-section-file-downloads
The LPV Legacy Stars is a subset of stars in the program. Michael Simonson and Kate Hutton applied a selection criteria to the LPV program to determine the "most" important stars out of this list of important stars. There is a LPV Legacy List for both the Northern and Southern Hemispheres.
In VSX, using the "campaign or program" selection box you can select either the LPV Program (388 stars) , LPV Legacy Program (121 stars), or LPV Legacy South (35 stars).
I hope this helps!
Rich Roberts
RRIA