Stars/Os/Quiz

HD 93129 is surrounded by the lesser stars of Trumpler 14 star cluster. Credit: NASA & ESA, Jesús Maíz Apellániz (Centro de Astrobiología, CSIC-INTA, Spain).

O stars is a lecture about an entity, source, and/or object observed using radiation astronomy that is classified as an O-type star.

You are free to take this quiz based on O stars. Once you've read and studied it, the links contained within, listed under See also, External links and the {{stars resources}} template, you should have adequate background to score 100 %.

Enjoy learning by doing!

Quiz

Point added for a correct answer:
Points for an incorrect answer:
Ignore the questions' coefficients:

1 O stars can be put into classes based on?

	luminosity
	size
	apparent mass
	temperature
	spectral lines
	composition

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

	Yes
	No

3 Which of the following is not a characteristic of O type stars?

	can be a spectroscopic binary
	the hottest stars
	can be a high-velocity star
	peak wavelength in the gamma-ray range
	orange color.

4 True or False, Alnitak is a triple star system with an O9.7 supergiant and an O9 giant as well as a B0 giant.

	TRUE
	FALSE

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

	TRUE
	FALSE

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

	TRUE
	FALSE

7 Gamma-ray stars have surface temperatures starting at 300,000,000 K (300 MK) corresponding to a peak wavelength of 0.010 nm (10 pm) for the beginning of super soft

sources.

8 True or False, X-ray stars have surface temperatures starting at 300,000 K corresponding to a peak wavelength of 10 nm for the beginning of super soft X-ray sources.

	TRUE
	FALSE

9 Which of the following is not a phenomenon usually associated with O-type SN progenitors?

	a blue supergiant
	an LBV
	a red supergiant
	an early W-R
	a WN

10 Complete the text:

On the main sequence for spectral classes 06-06.5, 07, and 08 one finds strong λ4686 absorption often accompanied by weak λλ4634-4640-4642 emission.

11 True or False, In 1947, G. E. Kron proposed that starspots were the reason for periodic changes in brightness on blue dwarfs.

	TRUE
	FALSE

Hypotheses

Main article: Hypotheses

1. Stars that emit light do so because they are receiving electron irradiation.

See also

• Astronomy/Quiz
• First astronomical X-ray source/Quiz
• Planetary science/Quiz
• Radiation astronomy/Quiz
• Radiation chemistry/Quiz
• Radiation geography/Quiz
• Stars/Quiz
• Stellar active region/Quiz

External links

• NASA/IPAC Extragalactic Database - NED
• The SAO/NASA Astrophysics Data System
• SIMBAD Astronomical Database