This graph shows the relationship between the temperature and brightness of a sampling of stars in the globular cluster M4. The line of dots at upper right represents main-sequence stars, those whose cores are fusing hydrogen. Normal stars like our Sun fall in the middle of this line.
The white dwarfs are not part of the main-sequence stars because they have used up their hydrogen fuel. These dying stars are fainter and yet hotter than their main-sequence relatives. NASA's Hubble Space Telescope hunted for the faintest and coolest of the white dwarfs [bottom of white dwarf population.]
Credits
NASA and A. Feild (STScI)| About The Object | |
|---|---|
| Object Name | M4, NGC 6121 |
| About The Object | |
|---|---|
| Object Name | A name or catalog number that astronomers use to identify an astronomical object. |
| Object Description | The type of astronomical object. |
| R.A. Position | Right ascension – analogous to longitude – is one component of an object's position. |
| Dec. Position | Declination – analogous to latitude – is one component of an object's position. |
| Constellation | One of 88 recognized regions of the celestial sphere in which the object appears. |
| Distance | The physical distance from Earth to the astronomical object. Distances within our solar system are usually measured in Astronomical Units (AU). Distances between stars are usually measured in light-years. Interstellar distances can also be measured in parsecs. |
| Dimensions | The physical size of the object or the apparent angle it subtends on the sky. |
| About The Data | |
| Data Description |
|
| Instrument | The science instrument used to produce the data. |
| Exposure Dates | The date(s) that the telescope made its observations and the total exposure time. |
| Filters | The camera filters that were used in the science observations. |
| About The Image | |
| Image Credit | The primary individuals and institutions responsible for the content. |
| Publication Date | The date and time the release content became public. |
| Color Info | A brief description of the methods used to convert telescope data into the color image being presented. |
| Orientation | The rotation of the image on the sky with respect to the north pole of the celestial sphere. |
