Blog
What is Time: JD
Julian Dates (JD) are a continuous count of days, and fractions of days, since noon Universal Time on January 1, 4713 BC (on the Julian calendar)
What is an Epoch
An epoch is a particular time period, point in history, or a moment defined by a particular event, and is a moment of time used as a reference point for a time-varying astronomical quantity.
Constellations
The result of countless different cultures naming the same stars, inconsistent star names have necessitated the need for a dependable and systematic method of stellar nomenclature based on the brightness of stars within any given constellation.
Locating your star in an image – Variable Stars and Exoplanets
This tutorial covers how to identify your target stars and the cardinal points, so you can place North and East in your images using MiraPro.
Parsecs and Light Years
Parsecs and light years are common measurements of distance to celestial objects, and the former is especially significant for its importance to scientific writing and its relationship with parallax.
Kepler’s Laws
Kepler's laws of planetary motion are: the orbits of the planets are ellipses with the sun at one focus, a line from a planet to the sun sweeps over equal areas in equal intervals of time, and a planet’s orbital period (P) squared is proportional to its average distance from the sun (a) cubed
Stellar Populations I, II, III
The three population (pop) classifications categorize stars based on how much metal is contained within them, and this concept of "pop" stars is sometimes crucial to research.
HR Diagram Overview
The HR Diagram is a stellar plot of Luminosity vs. Temperature, and can help to understand where in its "life cycle" a star is
EM Radiation Overview
The electromagnetic spectrum describes light, and all objects above 0 Kelvin emit light.
WCS Coordinates With Astrometry.Net
Astrometry.net is a highly effective tool that analyzes astronomical images and can determine the WCS coordinates of the image as well as details of the known celestial objects contained within it.
Radial Velocity
A measure of movement towards or away from the observer, radial velocity is just one component of stellar motion that is derived through measurement of the doppler effect.
Astrometry Overview
Astrometry is the area that deals with the positions and motions of celestial objects. It has two main scientific...
Telescopes: An Overview
Telescopes gather light from objects, and there are two main types: refractor (uses a lens to bend light) and reflector (uses a mirror to reflect light). Aperture and field of view are two main parameters of telescopes.
Angular Measurements of the Sky
When describing night-sky objects, spherical (not linear) measurements are used. These measurements are typically in degrees, arcminutes, and arcseconds.
Proper Motion
Proper motion is the change in (x, y) tangential motion of a star, and described in two coordinates: Right Ascension and Declination
Color and Temperature
Star color is based on its temperature (hotter stars are blue, while cooler stars are red), and the color/temperature of a star can be classified into stellar classes
Magnitudes: Absolute and Apparent
Magnitude is the brightness of a star, and the measures of magnitude are absolute (brightness as appears to observer) and apparent (measure of how much light is being put out by an object)
Wien’s Law
Wein's Law relates light intensity to temperature, stating that the peak wavelength is the inverse of temperature, and temperature and intensity are directly correlated.
Light Curve O-C Diagrams
The O-C, or Observed-Computed method studies period changes in variable stars by comparing the observed time of maximum brightness to the computed time. The O-C method is reflective of the cumulative effect of period changes.