Astro Catalogs

AAVSO Areas of Interest

The American Association of Variable Star Observers (AAVSO) serves as a dedicated research and outreach organization that allows both professionals and amateurs contribute to the vast and dynamic field of variable star research in countless unique ways.



The AAVSO Photometric All-Sky Survey (APASS) is a key all-sky survey that helps various research programs measure, adjust, and standardize their photometric systems.


Point Spread Function (PSF)

Point Spread Function (PSF) uses known optical behaviors of both stellar light and the imaging system to decrease the complexity of images and create visual separation between objects for more accurate study.


Aperture Photometry

Aperture Photometry, key to all studies in photometry, is one of the two most common methods of measuring the flux output of a star and is the most accurate when used with non-crowded images.

Variable Stars

Group Extrinsic

The extrinsic classification refers to eclipsing, rotating, and microlensing variable stars, all of which have flux variations as a result of external stellar factors.

CCD Cameras

SLOAN ugriz Filters

One of the two standardized filter sets used for BRIEF projects, SLOAN ugriz is widely used due to its distinct, low-overlap response curves and generally flexible and efficient nature.

CCD Cameras

Linearity and Saturation

As inherent consequences of the design of CCD photon collection, pixel saturation and non-linearity are common challenges that must be carefully managed for effective scientific imaging.

CCD Cameras

Imaging Basics

This video serves as a best practices checklist for night sky imaging and outlines both the basic and more advanced methods involved with astronomical imaging.

CCD Cameras

Full Width Half Maximum

Used to determine the quality of your image, the Full Width Half Maximum (FWHM) process is used to determine the quality of images and is of particular importance in photometric and exoplanet research work. BRIEF primarily uses the OSS Pipeline to account for the FWHM process.

CCD Cameras

Camera Overview

Charged Coupled Devices (CCDs) are an integral part of astronomical imaging that utilize a matrix of electronically-measured photon counts to accurately represent an image.


What is Time: BJD

Barycentric Julian Day (BJD) time is the universal day and time at the center of the solar system and is crucial to many astronomically-relevant processes as well as other time scales.


What is an Ephemeris

A highly useful concept for applications in both Double and Variable Stars, an Ephemeris is an estimation of where/when a particular astronomical event will occur at a particular time in the future.