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Bands in optical data in the AAVSO International Database

Bands in optical data in the AAVSO International Database (AID)

Each variable star observation in the AID contains a field that specifies the band (filter) used in making the observation.

For data downloaded from the AID using the data-download tool, the band is given as an abbreviation (e.g., visual is Vis, Johnson V is V).

In special cases, the band (e.g. visual) may be represented as a number (e.g., 0). The following numbers represents the following bands:

Alert Notice 703: TCP J21040470+4631129 images, photometry, and spectroscopy urgently requested - REVISED

Note: This Alert Notice was revised from its original text to correct a misinterpretation of the request from Dr. Echevarria, to update the recent observations, and to update the status of scheduled HST observations.  -  Elizabeth O. Waagen, 2 April 2020

April 2, 2020   (original issued April 1, 2020)

Exoplanets and the Search for Extraterrestrial Life

Variable Stars and the Stories They Tell: Exoplanets and the Search for Extraterrestrial Life

©February 2018 by Dale Alan Bryant

(In memory of M.I.T. astrophysicist Dr. Philip Morrison - who started all this...)


Though the figures are tough to keep up with - they are changing, almost daily - the Kepler Space Telescope (KST) has discovered, to date, over 4,500 exoplanet candidates, ~3,400+ of which have been confirmed.


VPhot is a member benefit of the AAVSO! Click here to join!

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:

All VPhot processing is done via a web browser. All of the basic photometry tools exist (stacking, time series analysis, control of annulus', transformation, etc.) and the algorithms have been rigorously checked and confirmed to be of the highest quality. Results of the processing are automatically exported in AAVSO Extended Format, meaning you can directly load them into our database via WebObs without having to make any changes to the data file. 

Please note that your images will be retained on the server for four months. After this time, they will be deleted automatically to save resources.

 Members can download the VPhot Users Guide.

 We also have an online VPhot Forum for your questions, comments and suggestions.

The following series of video tutorials have been produced by Ken Mogul. Some features may have changed since the tutorials were produced, but the core lessons are still applicable.

VPhot was originally published under another name. Click here to read why we ultimately chose the name VPhot.

VPhot is primarily the work of Geir Klingenberg (coding and design) and Arne Henden (photometry) with a cast of hundreds who have made suggestions, written tutorials and tested the software.

Request Comparison Stars for Variable Star Charts

[Note: If your variable star has an existing sequence, even if it is only one comparison star, please request assistance via CHET. This page is only for variables that have NO comparison stars. Thank you.]

CCD Photometry Guide - English

The Guide is available in .pdf format. You have the option either to download the entire publication or individual chapters. The complete Guide is 82 pages long.

AAVSO Guide to CCD Photometry (Version 1.1) (3.5 MB)

Special Notice #405: Request for Monitoring of V4641 Sgr

August 4, 2015:  Dr. Gregory Sivakoff (U. of Alberta) has requested optical monitoring of the galactic microquasar V4641 Sgr beginning immediately, and continuing for the next 120 days, or until it is no longer observable from your location.

Landolt Standards and 21st Century Photometry

Arlo Landolt should be familiar to most of the AAVSO community, not only as a friend and former councillor of the AAVSO, but as one of the leading figures of astronomical photometry and photometric calibrations.  Arlo Landolt's work on standard stars has set the standard -- very literally -- for astronomical photometry for nearly half a century.


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