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American Association of Variable Star Observers

American Association of Variable Star Observers
According to the magnetospheric accretion scenario, young low-mass stars are surrounded by circumstellar disks which they interact with through accretion of mass. The accretion builds up the star to its final mass and is also believed to power the mass outflows, which may in turn have a significant role in removing the excess angular momentum from the star-disk system. Although the process of mass accretion is a critical aspect of star formation, some of its mechanisms are still to be fully understood. On the other hand, strong flaring activity is a common feature of young stellar objects (YSOs). In the Sun, such events give rise to perturbations of the interplanetary medium. Similar but more energetic phenomena occur in YSOs and may influence the circumstellar environment.

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Cosmigraphics: Picturing Space Through Time in 4,000 Years of Mapping the Universe Long before Galileo pioneered the telescope, antagonizing the church and unleashing a “hummingbird effect” of innovation, humanity had been busy cataloging the heavens through millennia of imaginative speculative maps of the cosmos. We have always sought to make visible the invisible forces we long to understand, the mercy and miracle of existence, and nothing beckons to us with more intense allure than the majesty and mystery of the universe. Four millennia of that mesmerism-made-visible is what journalist, photographer, and astrovisualization scholar Michael Benson explores with great dedication and discernment in Cosmigraphics: Picturing Space Through Time (public library) — a pictorial catalog of our quest to order the cosmos and grasp our place in it, a sensemaking process defined by what Benson aptly calls our “gradually dawning, forever incomplete situational awareness.”

PLoS Biology : Publishing science, accelerating research A Peer-Reviewed, Open Access Journal Current Issue PLOS Biology is a peer-reviewed, open-access journal featuring research articles of exceptional significance in all areas of biological science, from molecules to ecosystems. 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.

Time delay The Astrophysical Journal, 521:L45-L48, 1999 August 10 © 1999. The American Astronomical Society. All rights reserved. Printed in U.S.A. A Method of Mass Measurement in Black Hole Binaries using Timing and High-Resolution X-Ray Spectroscopy A. Biology News Jan. 5, 2016 — Examination could hold wider applications on how stress during pregnancy affects mothers and ... read more Jan. 5, 2016 — Parasitoid wasps manipulate their caterpillar hosts into eating a more wasp-friendly diet, report investigators. It turns out that when caterpillars eat more carbs, the wasp larvae that chew their ... read more Jan. 5, 2016 — Eating increases the amount of damaging reactive molecules in the body, potentially shaping and constraining life history evolution across animal groups, new research on snakes ... read more

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.) Have an AAVSO observer code (Apply for an observer code - its free and automatic) Be logged into our web site. (Register for a web site account.) The Fundamentals of Stellar Astrophysics (by G.W. Collins II) Web Edition by G.W. Collins II Preface to the (2003) WEB Edition

Welcome page Website of Erik Verlinde Erik P. Verlinde Institute for Theoretical PhysicsUniversity of AmsterdamValckenierstraat 651018 XE, Amsterdam Email: 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.

Modified Julian Day Converter This converter requires the use of Javascript enabled and capable browsers. There are two converters in this script, the first converting from MJD to MM-DD-YYYY in the modern Gregorian calendar format. The second converts from the MM-DD-YYYY format to the MJD number. This converter is accurate from 1754 A.D. to current date. All entries are numeric; in the case of months, it is MM, with the MM being from 01 to 12.