Universe Guide


Delta Scuti - HD172748 - HIP91726

Delta Scuti is a blue to white pulsating giant star that can be located in the constellation of Scutum. Delta Scuti is the Bayer Classification for the star. HIP91726 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD172748. Delta Scuti has alternative name(s), del_Sct.

Location of Delta Scuti

The location of the star in the galaxy is determined by the Right Ascension (R.A.) and Declination (Dec.), these are equivalent to the Longitude and Latitude on the Earth. The Right Ascension is how far expressed in time (hh:mm:ss) the star is along the celestial equator. If the R.A. is positive then its eastwards. The Declination is how far north or south the star is compared to the celestial equator and is expressed in degrees. For Delta Scuti, the location is 18h 42m 16.42 and -09d03`09.2 .

Proper Motion of Delta Scuti

All stars like planets orbit round a central spot, in the case of planets, its the central star such as the Sun. In the case of a star, its the galactic centre. The constellations that we see today will be different than they were 50,000 years ago or 50,000 years from now. Proper Motion details the movements of these stars and are measured in milliarcseconds. The star is moving 0.82 ± 0.16 miliarcseconds/year towards the north and 9.21 ± 0.31 miliarcseconds/year east if we saw them in the horizon.

Physical Properties (Colour, Temperature, Radius) of Delta Scuti

Delta Scuti has a spectral type of F2IIIp d Del. This means the star is a blue to white giant star. The star has a B-V Colour Index of 0.35 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 6,967 Kelvin.

Delta Scuti has been calculated as 4.22 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 2,932,832.60.km.

Delta Scuti Apparent and Absolute Magnitudes

Delta Scuti has an apparent magnitude of 4.70 which is how bright we see the star from Earth. Apparent Magnitude is also known as Visual Magnitude. If you used the 1997 Parallax value, you would get an absolute magnitude of 0.91 If you used the 2007 Parallax value, you would get an absolute magnitude of 0.74. Magnitude, whether it be apparent/visual or absolute magnitude is measured by a number, the smaller the number, the brighter the Star is. Our own Sun is the brightest star and therefore has the lowest of all magnitudes, -26.74. A faint star will have a high number.

Distance to Delta Scuti

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 17.44 which gave the calculated distance to Delta Scuti as 187.02 light years away from Earth or 57.34 parsecs. It would take a spaceship travelling at the speed of light, 187.02 years to get there. We don't have the technology or spaceship that can carry people over that distance yet.

In 2007, Hipparcos data was revised with a new parallax of 16.11 which put Delta Scuti at a distance of 202.46 light years or 62.07 parsecs. It should not be taken as though the star is moving closer or further away from us. It is purely that the distance was recalculated.

Variable Type of Delta Scuti

The star is a pulsating Delta Scuti variable type which means that its size changes over time. The Variable Type is usually named after the first star of that type to be spotted. Delta Scuti brightness ranges from a magnitude of 5.000 to a magnitude of 5.000 over its variable period. The smaller the magnitude, the brighter the star.

Source of Information

The source of the information if it has a Hip I.D. is from Simbad, the Hipparcos data library based at the University at Strasbourg, France. Hipparcos was a E.S.A. satellite operation launched in 1989 for four years. The items in red are values that I've calculated so they could well be wrong. Information regarding Stellar Age, Metallicity or Mass is from the E.U. Exoplanets. The information was obtained as of 12th Feb 2017.

Delta Scuti Facts

Alternative Names

Short Namedel Sct
Bayer DesignationDelta Scuti
Hipparcos Library I.D.91726
Bonner DurchmusterungBD-09 4796
Henry Draper Designation172748

Visual Facts

Star Typegiant star
Absolute Magnitude0.91 / 0.74
Apparent Magnitude4.70
Right Ascension (R.A.)18h 42m 16.42
Declination (Dec.)-09d03`09.2
1997 Distance from Earth17.44 Parallax (milliarcseconds)
 187.02 Light Years
 57.34 Parsecs
2007 Revised Distance from Earth16.11 Parallax (milliarcseconds)
 202.46 Light Years
 62.07 Parsecs
Proper Motion Dec.0.82 ± 0.16 milliarcseconds/year
Proper Motion RA.9.21 ± 0.31 milliarcseconds/year
B-V Index0.35
Spectral TypeF2IIIp d Del
Colour(F) blue to white

Variable Star Details

Variable Star ClassPulsating
Variable Star TypeDelta Scuti

Estimated Facts

Radius (x the Sun)4.22
Calculated Effective Temperature6,967 Kelvin

Sources and Links

SIMBAD SourceLink

Related Stars

Multi-Star System

The star has been identified as being a multi-star system, one in which there is at least one star in close orbit to another star or two or more stars orbiting a central point. The stars may be of equal mass, unequal mass where one star is stronger than the other or be in groups orbiting a central point which doesn't necessarily have to be a star. More information can be found on my dedicated multiple star systems page. The source of the info is Simbad. The file is dated 2000 so any differences between this and any other source will be down to the actual source from where the information came from.

Proper Motion mas/yr
H.D. IdB.D. IdStar CodeMagnitudeR.A.Dec.SpectrumColourYear
172748-09 4796.0A4.700007.000001.00000F0Yellow/White
-09 4797.0C9.200001879

Location of Delta Scuti in Scutum

Delta Scuti (Delta Scuti) Location in Scutum

The map was generated using Night Vision, an awesome free application by Brian Simpson.

Add a Comment

Email: (Optional)