Pulsars

A neutron star is unimaginably dense. It contains the mass of the Sun, but has that mass squeezed into a ball perhaps 20km (12 1/2 miles) across. Further, neutron stars are so small that they can spin very rapidly, many times per second or faster. When they spin they emit electromagnetic radiation which can appear as flashes from earth.

If the magnetic pole of the neutron star is "pointed" [See related link - Pictorial of pulsar] towards Earth, they are called pulsars, as they "pulse" as they spin and can be detected.

The flashes produced by the pulsars are detected as the electro magnetic radio waves caught up by the radio telescopes

Pulsars emit electromagnetic radiation across a wide range of wavelengths, from radio waves to X-rays and even gamma rays. The most prominent emission is usually in the form of radio waves, which is why pulsars are often observed using radio telescopes.

Pulsars are formed from the cores of massive stars that have exploded in supernovae. During the collapse, their magnetic fields get amplified to extremely high levels due to conservation of magnetic flux. This results in pulsars having large magnetic fields.

Your question can not be answered exactly as it is asked. Many of the things in the universe come in various sizes. There are Galaxies and there are Super Galaxies. Super Galaxies can be bigger than clusters of galaxies. Planets and Moons come in all kinds of sizes. Some moons are the size of some minor and/or regular planets... such as Ganymede, and Titan for example. Both are larger than Mercury, and the minor planet Pluto. Pulsars are the remnants of a dying star, stars, meteors, and every thing you have asked about come in various sizes as well. I would recommend that you find and watch "The Universe" which I believe is on the Discovery Channel. There is an episode that deals with the largest things in the Universe. According to that source... the largest thing in the Universe is the "Cosmic Web". This show will deal with pretty much everything you have on your list. It is a very interesting show, and it repeats regularly.

If your Pulsar watch's light isn't staying on, it could be due to a dead battery or a malfunction in the light mechanism. I recommend getting the watch checked by a professional at an authorized service center to diagnose and fix the issue.

Most pulsars are detected purely through luck. Many organizations have radio telescopes constantly scanning the skies for signals, sometimes one picks up a regular periodic signal, if it is properly periodic, we know it's at least a pulsar or a quasar, further research would discern exactly what.

The first pulsar was found by Jocelyn Bell Burnell and Antony Hewish in July 1967.

Because they had not idea what they had discovered they called the new object LGM-1, for "little green men". It was later determined to be a pulsar [See related question]. Their pulsar was later dubbed CP 1919, and is now known by a number of other designators.

See related link for more information.

The $P \dot{P}$ diagram is used to follow the lives of pulsars, playing a role similar to the HR diagram for ordinary stars. It encodes a large amount of information about the pulsar population and its properties. Using the parameters, one can estimate the pulsar age, magnetic field and spin down power. [See Link]

From:- The Handbook of Pulsar Astronomy

Because of the conservation of rotational momentum. As a stars core collapses, it retains the original rotational velocity. As a pulsar or neutron star's original size was in the region of 60,000 time greater that it's current form, the rotational speed is multiplied by this factor.

Maintaining the rotational momentum requires the star to spin faster.

Pulsars are best observed in the radio part of the electromagnetic spectrum. This is because their strong radio emission allows them to be detected and studied using radio telescopes. However, pulsars have also been observed at other frequencies, including X-ray and gamma-ray wavelengths.

A periodic signal has two major characteristics: frequency and amplitude. Frequency is the number of times the periodic signal occurs in a set time, and the amplitude refers to how strong the signal is.

No. A pulsar is a neutron star.

Pulsar Stargrave was created in 1977.

The Pulsars was created in 1994.

radio telescopes

Humans are able to detect pulsars when one of their beams crosses paths with the Earth. When this happens, we are able to detect the resulting electromagnetic radiation in the radar spectrum.

All young neutron stars in reality are "pulsars".

However, for a neutron star to be termed a pulsar, it's magnetic axis has to point towards Earth. (So we can see the pulse, even though all young neutron stars have a pulse, they cannot be observed from Earth.)

A pulsar is a neutron star that rotates and sends a beam of electromagnetic radiation. This is known because only a very dense source of such radiation would be capable of rotating that quickly without disintegrating.

1. Cluster
2. Spiral
3. Red giant
4. Pulsar
   

A Pulsar is highly magnetised, rotating neutron star that emits a beam of electromagnetic radiation.

No. Some supernova remnants contain black holes.

As far as light can travel

Several light years. Of course, that would depend on the nature of the life; we wouldn't want humans to settle any planet within several light years of an active pulsar. For other hypothetical lifeforms with a greater resistance to hard X-rays, this might not be an issue. Or, if you don't mind a ferocious mutation rate, which we suspect that a high radiation dose would cause.

Has it's magnetic axis directed towards Earth

A "pulsar" is a rapidly rotating neutron star. The pulses are pulses of X-rays or gamma rays that are radiated continuously, but which are only detectable when the beam is pointed at the Earth.

It seems likely that there are a great number of rotating neutron stars that do not happen to point at the Earth. They would not, therefore, be detectable.