Skip to main content

photometry

VPhot

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.

The AAVSO Research Portal

Welcome to the AAVSO's Research Portal.  From this page, you can find information about obtaining AAVSO data, requesting new observations, or learning more about the AAVSO, its data, and its services for the research community.  Its purpose is to facilitate your use of the AAVSO's resources in your research efforts.

See the blue boxes on the right hand side of this page to access the AAVSO data archives or to find out  how to work with the AAVSO to obtain new scientific data.

 

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

The AAVSO Guide to CCD Photometry, first published in September 2014, is designed to be a basic introduction and guide to using CCDs to perform photometry of variable stars. With care, you can use a backyard telescope to obtain astrophysically useful data that matches the quality of those produced by professional astronomers, using exactly the same principles and techniques that are used at larger research observatories around the world.

Exoplanets and the Search for Extraterrestrial Life

 Variable Stars and the Stories They Tell:  

Exoplanets and the Search for Extraterrestrial Life

by Dale Bryant   

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.

SSP-4 Photometer Observation Reports and Analyses

This information was originally published as a series of reports by AAVSO observer Doug West in 2003, outlining his experiments and calibrations of the Optec SSP-4 infrared photometer

SSP-4 Photometer Observation Report and Analysis #1

By Doug West
16 May 2003

Pages

AAVSO 49 Bay State Rd. Cambridge, MA 02138 aavso@aavso.org 617-354-0484