What is the apparent size?
The apparent size of the object in space is how clear it seems, taking into account the effect of the Earth's atmosphere. The lighter object has a lower size than the more dark. The apparent size scale is logarithmic, so a star would be about two and a half times brighter than the absolute size of two. Obvious size is commonly used measurements in astronomy because it allows direct comparison of the relative brightness of two objects. When the stars where the first were categorized, the star with the size of one was considered the brightest category. A star in category six was the smallest thing the human eye could see. Since then, the use of binoculars has meant that even more distant and darkened stars can now be seen. For example, the Hubble Space Telescope can see objects up to 31.5.
The obvious brightness of the star depends on its size and distance from the ground. This is because the force emitted by the star is monitored by an inverse square law, which means that if the distance is doubled, the force will be reducedby four. For this reason, the obvious size may only provide limited information about the object unless other variables are known.
While the obvious size is JAB, as can be seen from the ground, the absolute size is to measure the actual brightness of the object. In many situations, the absolute size is more useful than the obvious size because it takes into account the distance of the object. The apparent brightness of the star or other object must be known before it can be calculated absolute size.
An important aspect of measuring size is the frequency of emitted light. All lighting tools have a number of sensitivity depending on the measured light, so the apparent brightness in one wave zone may vary from brightness in another. To take into account this, any measurement of apparent size must include details of how it has been obtained.
Some examples include the maximum brightness of Venus, which is -4.1; Sirius, the brightest starDA in the sky that is -1.47; And the maximum brightness of Pluto, which is 13.65. The sun has a size of -26.7, which makes it the brightest object in the sky. For comparison, the full moon has only -12.6 size.