Fine lines or webs used in the focal plane eyepiece are called Reticle. It is used for centering objects or as a guide for making angular measurements. It is commonly used for telescopes, cameras and even rifles. It is also known as graticule. The lines on the reticle are also typically illuminated.
When you look at stars in the night sky, it appears like they are just tiny dots of light that look the same. However, they are millions of lights years away, stars look very different from how they appear at night. They are in fact classified into several types according to their size, temperature, and brightness.
A radiometer is a device used for measuring different types of electromagnetic radiation or energy that exhibit wave-like properties. All objects that have a temperature beyond absolute zero are able to radiate this type of energy into the space surrounding them. This is also true for objects found in space such as stars and even whole galaxies.
A refracting telescope is one of the earliest tools used by astronomers from way back to study outer space and distant objects. It is one of the two kinds of optical telescopes and uses a lens as the light gathering part or the objective as opposed to a mirror that is commonly used as the objective by reflecting telescopes.
The Sun, Moon, stars and other celestial objects are beyond the reach of any instrument that can be used by observers here on Earth. Measuring the distance of a celestial object from the Earth might seem to be complicated. But measuring the distance of these remote entities have been simplified by the concept of parallax.
There are many terms in astronomy, and there is no doubt about that. One of which is the concept of Obliquity, more commonly known as the axial tilt. The angle between a certain rotational axis of an object and the specific perpendicular line in regards to the object’s orbital plane is better known as its obliquity.
Photo by: Rama Creative Commons Not only does astronomy cover different branches of science, it also borrows concepts in fiber optics as well. Objective (optics) is also taken into account when it comes to science, or in this case, astronomy.
The Rotation period is the time required for a body to rotate around its axis. The lower the period means the greater rotation boost it has. This differs greatly from the planet’s solar day, which would include an extra fractional rotation which is needed to furnish the portion of the planet’s orbital period during one day.
What do you think of a Reusable launch vehicle (RLV)? It is a system that is capable of launching a launch vehicle to space more than once. It is different from expendable launch systems, wherein each launch vehicle is only launched only once and then discarded. Currently no true reusable launch vehicle is in use. The closest one that can be compared is the space shuttle.
What is Right ascension? This is the term astronomer’s use for one of the two coordinates of a point right on the celestial sphere when using the equatorial coordinate system. The other coordinate is referred to as declination. It is said that the concept of RA has been known since the time of Hipparchus. It is often expressed in units of time rather than degrees of arc. The symbol for this is the Greek letter a meaning alpha.