I can't tell you now the distance in lightyears or what star this was, though you can see it with the naked eye at night in this hemisphere.

Tau Ceti is noted for being the nearest Sun-like star at a distance of 11. 9 light-years.

Its distance is unusual for a naked-eye star.

ω Centauri ( NGC 5139 ), despite being listed as the constellation's " omega " star, is in fact a naked-eye globular cluster, located at a distance of 17, 000 light-years with a diameter of 150 light-years.

In the Halo franchise, the weak, low-ranking Grunts of the Covenant originate on a frozen exoplanet named Balaho, where methane is a primary constituent of the atmosphere, prevents the planet becoming even more frigid than it already is due to its distance from its parent star, and thus, Grunts have evolved to utilize the gas for respiration.

Spectroscopy is also used in the determination of the distance of a star, using the red shift.

where R < sub > s </ sub > is the radius of the star, R < sub > o </ sub > is the occulting object's radius, and r is the distance from the star to the occulting object.

With this work under his belt, Bessel was able to achieve the feat for which he is best remembered today: he is credited with being the first to use parallax in calculating the distance to a star.

In 2007, using the Keck telescope, a team from California Institute of Technology found six star forming galaxies about 13. 2 billion light years ( light travel distance ) away and therefore created when the universe was only 500 million years old.

With an apparent brightness of 0. 03m, this is the second brightest star of the northern hemisphere ( after Arcturus ) and the fifth brightest star in all ; its spectral class is A0 V and it lies at a distance of only 25. 3 ly.

The following year he began studying star clusters ; large groupings of stars that are co-located at approximately the same distance.

This places the cloud at nearly a quarter of the distance to Proxima Centauri, the nearest star to the Sun.

Space is sufficiently rarefied that most lines from the Earth do not touch any star within this distance of Earth.

Mathematically, the light received from stars as a function of star distance in a hypothetical fractal cosmos is:

L ( r ) = average luminosity per star at distance r ;

Nurmi had won five gold medals in five events, but he left the Games embittered as the Finnish officials had allocated races between their star runners and prevented him from defending his title in the 10, 000 m, the distance that was dearest to him.

The first direct measurement of the distance to a star ( 61 Cygni at 11. 4 light-years ) was made in 1838 by Friedrich Bessel using the parallax technique.

The only exception is a faint image of a large star cluster containing hundreds of thousands of stars located one billion light years away — ten times the distance of the most distant star cluster previously observed.

It consists of two large spiral galaxies in the process of colliding with their nuclei orbiting at a distance of 1, 200 light-years, causing extensive star formation throughout both components.

* α Sge: also known as Sham, this yellow bright giant star of spectral class G1 II ( with 4. 37m ) lies at a distance of 610 light-years and together with β Sge ( also 4. 37m ) forms either the feathers of the shaft or the two-pointed arrow once used in the Roman army.

A sextant can also be used to measure the Lunar distance between the moon and another celestial object ( e. g., star, planet ) in order to determine Greenwich time which is important because it can then be used to determine the longitude.

At a distance of just under 12 light-years from the Solar System, it is a relatively nearby star.

We assume for this illustration that the size of the land plots is so great that the distance between dwellings is greater than the voice can carry and that most of the communication is between nearest neighbors only, as shown in Figure 2.

But he, as I can now retort, was the man who could see so short a distance ahead that after a visit to Russia he gave voice to the famous exclamation: `` I have seen the future and it works ''.

But during nighttime hours the skywave radiations are reflected from the ionosphere, thereby creating the possibility of one station's rendering service, via skywave, at a much greater distance than it can through its groundwave signal, and at the same time vastly complicating the interference problem because of the still greater distance over which these skywave signals may cause interference to the signals of stations on the same and closely adjacent frequencies.

These can also move a short distance but at right angles to the tappets.

Improvement can be measured by the lessening distance between toes and head.

This distribution can be summarized by averaging the distance in grades apart: Af ; ;

Using this distance and other photographs, more information about the object, including its orbital elements, can be obtained .< ref >

" The small-angle formula can be used to convert such an angular measurement into a distance / size ratio.

1st century BCE ), shows how the distance to the Sun can be computed geometrically, using the different lengths of the noontime shadows observed at three places 1000 li apart and the assumption that the Earth is flat.

It can be reached by underground railway ( although the stations are at a distance from the Park and at a much lower level below the hill ), by city buses, or by commercial tourist buses.

One can compute the absolute magnitude of an object given its apparent magnitude and luminosity distance:

You can also compute the absolute magnitude of an object given its apparent magnitude and distance modulus:

Given the absolute magnitude, for objects within our galaxy you can also calculate the apparent magnitude from any distance ( in parsecs ):

However, the energy must be imparted over a limited distance ( determined by arm length ) and therefore ( because the projectile is accelerating ) over a limited time, so the limiting factor is not work but rather power, which determined how much energy can be added in the limited time available.

This work is stored in the bow as elastic potential energy, and when the bowstring is released, this stored energy is imparted to the arrow much more quickly than can be delivered by the muscles, resulting in much higher velocity and, hence, greater distance.

It can send and receive messages to and from a corresponding device over any distance whatsoever with no delay.

In the " Enderverse ", the two quarks inside a pi meson can be separated by an arbitrary distance while remaining connected by " philotic rays ".

Also, if laced together with rope instead of wire, the rope can be very quickly destroyed by such fires, after which the abatis can be quickly pulled apart by grappling hooks thrown from a safe distance.

6 ) at a finite distance from the axis ( or with an infinitely distant object, a point which subtends a finite angle at the system ) is, in general, even then not sharply reproduced, if the pencil of rays issuing from it and traversing the system is made infinitely narrow by reducing the aperture stop ; such a pencil consists of the rays which can pass from the object point through the now infinitely small entrance pupil.

For the case of an object that is small compared with the radial distance to its axis of rotation, such as a tin can swinging from a long string or a planet orbiting in a circle around the Sun, the angular momentum can be expressed as its linear momentum,, crossed by its position from the origin, r. Thus, the angular momentum L of a particle with respect to some point of origin is

Field evaporation is an effect that can occur when an atom bonded at the surface of a material is in the presence of a sufficiently high and appropriately directed electric field, where the electric field is the differential of electric potential ( voltage ) with respect to distance.