Transform Applier As you work your way up the learning curve of CCD photometry one of the later refinements is to develop transform coefficients for your telescope/filter/CCD camera setup. There are several references from the AAVSO website on how to do this and I’ve included some of them below. Once you have your coefficients you need to apply them to your observations. This can be a confusing process and usually involves transcribing your data to various spreadsheets. I offer here an application that is meant to make that process of applying your coefficients simple, consistent and easily traceable. There is still open discussion on how exactly you should apply your coefficients. And then Lou Cohen’s article tries to explain it further and correct minor errors : Cohen, Lou. The process I have in Transformer is to take the file with your untransformed observations and have the Transformer application scan it and rewrite it with the transformed observations.
VPHOT VPhot is an online tool for photometric analysis. You can upload your own FITS images to VPhot or have images taken via the AAVSOnet robotic telescope network automatically sent to your VPHOT account. To use VPhot you must: Be an AAVSO member (Apply for membership.) All VPhot processing is done via a web browser. We also have an online VPHOT Forum for your questions, comments and suggestions. The main VPhot interface with some sample images loaded. The following series of video tutorials have been produced by Ken Mogul.
VSP The Variable Star Plotter (VSP) is the AAVSO's online chart plotting program that dynamically plots star charts for any location on the sky, or for any named object currently in the Variable Star Index (VSX). By creating charts this way, every chart utilizes the most current data available. Through the use of unique Chart IDs generated by the Variable Star Plotter, one user can plot a chart, and another user in different part of the world can plot an identical chart by simply using the same Chart ID. The Variable Star Plotter is the tool you should use to create any chart that you would like to use. By entering an object name or its coordinates on the sky, the Variable Star Plotter can produce a star chart for that object or location, and tailor it to your specific observing requirements. For detailed instructions on using VSP, consult the Help Guide. If you need further assistance, you can email us at aavso@aavso.org. WHAT IS THE NAME, DESIGNATION, OR AUID OF THE OBJECT?
Eyes-on-the-Skies.org - Solar Robotic Telescope Observatory Dlaczego zmienne? Dlaczego akurat gwiazdy zmienne? Nie wiem, nie potrafię tego wyjaśnić w paru słowach. Na taką moją decyzję złożyło się bez wątpienia kilka lat doświadczeń w prowadzeniu wszelkiego rodzaju obserwacji. Większości z nich zaprzestałem po krótszych lub dłuższych okresach. Na początek odpowiedzmy sobie na pytanie, czym jest gwiazda zmienna? Jak się okazuje, gwiazdy zmienne wzbudzają wśród wielu miłośników astronomii duże zainteresowanie. Historia obserwacji gwiazd zmiennych sięga XVI wieku, kiedy to w 1596 roku mnich D. Pionierem odmiennego, metodologicznego podejścia do gwiazd zmiennych był F. Obecnie skatalogowanych jest grubo ponad 30 000 gwiazd zmiennych, a kilkanaście tysięcy czeka na potwierdzenie swojej zmienności. Najogólniej gwiazdy zmienne można podzielić na dwie grupy: Gwiazdy zmienne fizycznie. Pierwsze stanowią bardzo rozmaitą klasę obiektów, u których zmiany jasności są spowodowane zmianami ich parametrów fizycznych, takich jak temperatura, rozmiary itp. Literatura:
Project VS-COMPAS | Variable Stars Common Observation Mission in Particular Areas of the Sky La Sagra Sky Survey Z CamPaign - CVnet- The AAVSO Cataclysmic Variable Section 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. 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 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. Oddballs 1.