They are very bright or luminous stars.
main-sequence stars
That's short for Hertzsprung-Russel diagram. It is a diagram in which the total luminosity versus color (and therefore temperature) of many stars is plotted.
An H-R Diagram (Hertzsprung and Russell) is used to classify stars based on their size and brightness. The main sequence stars, such as our sun, are the medium stars, and take up the middle f the diagram, while the giants and dwarves are located on either side. http://www.eso.org/public/outreach/eduoff/cas/cas2002/cas-projects/bulgaria_comaber_1/hr_local.gif <- shows what an H-R diagram looks like.
The Lepus Constellation, "Lepus" meaning 'Hare'. The formation of the quadrilateral stars is known as 'Arsh-al-Jawza'.
The ancients believed that the firmament was a dome which held up the waters above, separating them from the waters below. Later in the first creation story, the sun, moon and stars are simply small lights placed in this firmament.
The largest stars are found in the upper-left portion of the H-R diagram, known as the "supergiant" region. The smallest stars are found in the lower-right portion of the diagram, known as the "dwarf" region.
The brightest star on the Hertzsprung-Russell diagram is typically found in the upper left corner, representing massive, hot, and luminous stars known as supergiants or giants. These stars have high luminosities and are located in the top portion of the diagram.
Stars that are cool and dim would be found in the lower right corner of the Hertzsprung-Russell diagram, in the region known as the "lower right" or "lower main sequence." These stars have low luminosity and temperature compared to other stars on the diagram.
The brightest stars on the Hertzsprung-Russell (HR) diagram are typically found in the top-left corner, known as the "upper main sequence." These stars are massive and luminous, such as blue supergiants or O-type stars. They have high temperatures and emit large amounts of energy.
One graph used to relate stars' absolute magnitudes and their spectral types is the Hertzsprung-Russell diagram, better (and more simply) known as the H-R diagram.
The H-R diagram constructed from the data on the brightest stars differs from the diagram constructed from data on the nearest stars because the brightest stars are typically more massive and have higher luminosities, while the nearest stars may include a mix of different masses and luminosities. This leads to a different distribution of stars in the diagram, with the brightest stars clustering in different regions compared to the nearest stars.
Cool and luminous stars would be located in the top right corner of a Hertzsprung-Russell diagram, in the region known as the red giant branch.
The HR diagram contains only stars - so everywhere.
The HR diagram, also known as the Hertzsprung-Russell diagram, depicts the relationship between the luminosity and temperature of stars. It shows how stars are distributed in terms of their brightness and temperature, allowing astronomers to classify stars based on these characteristics.
Neutron stars are significant on the Hertzsprung-Russell diagram because they represent the final stage of stellar evolution for massive stars. They are located in the lower left corner of the diagram, known as the "degenerate dwarf" region, due to their small size and high density. Neutron stars help scientists understand the life cycle of stars and the different stages they go through.
The location on the Hertzsprung-Russell (HR) diagram where most stars lie is known as the main sequence. The HR diagram is a plot of stellar luminosity against surface temperature. The main sequence is a prominent band that extends diagonally across the HR diagram from high temperature and high luminosity to low temperature and low luminosity. The majority of stars, approximately 90% of all stars, are situated along the main sequence on the HR diagram. These stars are often referred to as main-sequence stars. They exhibit a smooth relationship between surface temperature and luminosity, with varying sizes and masses but sharing this common characteristic of lying on the diagonal band from the upper left to the lower right of the HR diagram. Source: Teach Astronomy - The Hertzsprung-Russell Diagram
A Hertzsprung-Russell (H-R) diagram, also known as a color-magnitude diagram, is a graph that plots stars based on their absolute magnitude (brightness) and spectral type (color). It is a valuable tool for studying the properties and evolutionary stage of stars within a specific population.