Ultraviolet stars is a lecture that may become part of the radiation astronomy course on the principles of radiation astronomy and is included in the star courses.

Alnitak is a triple star system with an O9.7 supergiant and an O9 giant as well as a B0 giant. These stars illuminate the nearby Flame Nebula. Credit: Mdf, 2MASS/G. Kopan, R. Hurt.

You are free to take this quiz based on ultraviolet stars at any time.

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Quiz edit


1 Complete the text:

Ordinary glass is partially

to UVA but is

to shorter wavelengths, whereas silica or

glass, depending on quality, can be

even to vacuum UV wavelengths.

2 Complete the text:

The First Byurakan Survey commenced in 1965 using the

telescope at the Byurakan Astrophysical Observatory. The purpose of the survey was to find galaxies with an


3 Which of the following is associated with the ultraviolet?

black light
Charles Stuart Bowyer
Hα emission
PG 1159

4 True or False, The surface of the Sun is readily imaged in the ultraviolet.


5 Complete the text:

Match up the radiation letter with each of the detector possibilities below:
Optical rays - L
Visual rays - M
Violet rays - N
Blue rays - O
Cyan rays - P
Green rays - Q
Yellow rays - R
Orange rays - S
Red rays - T
multialkali (Na-K-Sb-Cs) photocathode materials



broad-band filter centered at 404 nm


thallium bromide (TlBr) crystals


18 micrometers FWHM at 490 nm

wide-gap II-VI semiconductor ZnO doped with Co2+ (Zn1-xCoxO)


6 Complete the text:

The spectral region bounded on the long wavelength side by the atmospheric

absorption and on the short wavelength side by the photoionization of interstellar

is the ultraviolet.

7 Complete the text:

To measure the color index, observe the magnitude of the object successively through two different filters such as

and blue (B), or blue and


8 True or False, Spectroscopically Zeta Puppis is classified as O4 I.


9 Complete the text:


series is the series of transitions and resulting ultraviolet emission lines of the

atoms as an electron goes from a high-energy level to an n =


10 True or False, BI 253 is an O2V star in the Large Magellanic Cloud.


11 Complete the text:

Match up the object viewed in the ultraviolet with its image:
Sun's chromosphere- L
calcite - M
Venus - N
Jupiter's aurora - O
Jupiter - P
Io - Q
Saturn - R
Betelgeuse - S
Mira - T
LAB-1 - U
Messier 101 - V












12 True or False, The first direct observation of waves propagating into and through the solar corona was made in 1997 with the SOHO space-borne solar observatory.


13 Which of the following radiation phenomena are associated with the ultraviolet?

He II lines
B I line
Be II lines
carbon III line
Hβ emission
oxygen O I lines

14 Yes or No, Stellar class O stars have surface temperatures high enough that most of their luminescence is in the ultraviolet.


Hypotheses edit

  1. Ultraviolet radiation can be an indicator of surface fusion above the photosphere of stars.

See also edit

External links edit

{{Radiation astronomy resources}}