What is the main criterion used to classify stars?
A) Luminosity
B) Temperature
C) Size
D) Distance
Answer: B) Temperature
Which spectral type corresponds to the hottest stars?
A) O
B) M
C) K
D) G
Answer: A) O
Which spectral type corresponds to the coolest stars?
A) O
B) M
C) K
D) G
Answer: B) M
What is the sequence of stellar spectral types from hottest to coolest?
A) OBAFGKM
B) MGFABKO
C) KMABFGO
D) GFMABKO
Answer: A) OBAFGKM
What characteristic feature of a star determines its spectral type?
A) Radius
B) Luminosity
C) Chemical composition
D) Surface temperature
Answer: D) Surface temperature
Which color is associated with a star of spectral type A?
A) Blue
B) White
C) Yellow
D) Red
Answer: B) White
Which spectral type is our Sun classified as?
A) O
B) G
C) M
D) F
Answer: B) G
What is the luminosity class of a main-sequence star?
A) I
B) II
C) III
D) V
Answer: D) V
What is the luminosity class of a giant star?
A) I
B) II
C) III
D) V
Answer: C) III
What is the luminosity class of a supergiant star?
A) I
B) II
C) III
D) V
Answer: A) I
What does the luminosity class II signify in stellar classification?
A) Main sequence
B) Giant
C) Supergiant
D) Subdwarf
Answer: B) Giant
Which luminosity class represents stars with the highest luminosity?
A) I
B) II
C) III
D) V
Answer: A) I
Which luminosity class represents stars with the lowest luminosity?
A) I
B) II
C) III
D) V
Answer: D) V
What is the luminosity class of a white dwarf star?
A) I
B) II
C) III
D) V
Answer: D) V
What does the luminosity class IV signify in stellar classification?
A) Main sequence
B) Subgiant
C) Supergiant
D) White dwarf
Answer: B) Subgiant
What is the approximate temperature range of an O-type star?
A) 3,000-4,000 K
B) 5,000-6,000 K
C) 10,000-30,000 K
D) 40,000-50,000 K
Answer: C) 10,000-30,000 K
Which spectral type has the shortest lifespan?
A) O
B) M
C) G
D) K
Answer: A) O
Which spectral type has the longest lifespan?
A) O
B) M
C) G
D) K
Answer: M
Which spectral type is the most common in the universe?
A) O
B) M
C) G
D) K
Answer: M
What is the luminosity class of a star that has exhausted its nuclear fuel and collapsed to a small size?
A) I
B) II
C) III
D) V
Answer: D) V
What is the primary factor that determines a star’s spectral type?
A) Age
B) Size
C) Temperature
D) Mass
Answer: C) Temperature
What characteristic of a star’s spectrum provides information about its chemical composition?
A) Emission lines
B) Absorption lines
C) Continuum spectrum
D) Doppler shift
Answer: B) Absorption lines
What is the spectral type of a star with a surface temperature of approximately 5,500 K?
A) O
B) G
C) M
D) A
Answer: B) G
What is the spectral type of a star with a surface temperature of approximately 3,000 K?
A) O
B) G
C) M
D) A
Answer: C) M
Which spectral type has the most prominent hydrogen absorption lines?
A) O
B) M
C) G
D) K
Answer: A) O
Which of the following is not a part of the spectral classification system?
A) Luminosity class
B) Color index
C) Surface gravity
D) Metallicity
Answer: B) Color index
Which luminosity class represents stars that are still in the process of contracting?
A) I
B) II
C) III
D) T Tauri
Answer: D) T Tauri
What is the surface temperature range of a K-type star?
A) 3,000-4,000 K
B) 5,000-6,000 K
C) 7,000-8,000 K
D) 10,000-30,000 K
Answer: B) 5,000-6,000 K
What is the surface temperature range of an A-type star?
A) 3,000-4,000 K
B) 5,000-6,000 K
C) 7,000-8,000 K
D) 10,000-30,000 K
Answer: C) 7,000-8,000 K
Which spectral type has the strongest hydrogen absorption lines?
A) O
B) M
C) G
D) K
Answer: A) O
Which spectral type has the weakest hydrogen absorption lines?
A) O
B) M
C) G
D) K
Answer: M
What characteristic of a star’s spectrum provides information about its radial velocity?
A) Emission lines
B) Absorption lines
C) Continuum spectrum
D) Doppler shift
Answer: D) Doppler shift
What does the luminosity class Ia signify in stellar classification?
A) Main sequence
B) Giant
C) Supergiant
D) White dwarf
Answer: C) Supergiant
What is the luminosity class of a star that is still in the process of formation?
A) I
B) II
C) III
D) T Tauri
Answer: D) T Tauri
What is the luminosity class of a star that has exhausted its nuclear fuel and collapsed to a small size?
A) I
B) II
C) III
D) V
Answer: D) V
What is the luminosity class of a star that is transitioning off the main sequence?
A) I
B) II
C) III
D) IV
Answer: D) IV
Which luminosity class represents stars with the highest luminosity?
A) I
B) II
C) III
D) V
Answer: A) I
What does the luminosity class IV signify in stellar classification?
A) Main sequence
B) Subgiant
C) Supergiant
D) White dwarf
Answer: B) Subgiant
What is the luminosity class of a star that has exhausted its nuclear fuel and collapsed to a small size?
A) I
B) II
C) III
D) V
Answer: D) V
What is the luminosity class of a star that is still in the process of formation?
A) I
B) II
C) III
D) T Tauri
Answer: D) T Tauri
What is the approximate temperature range of a G-type star?
A) 3,000-4,000 K
B) 5,000-6,000 K
C) 7,000-8,000 K
D) 10,000-30,000 K
Answer: B) 5,000-6,000 K
What is the surface temperature range of an F-type star?
A) 3,000-4,000 K
B) 5,000-6,000 K
C) 7,000-8,000 K
D) 10,000-30,000 K
Answer: C) 7,000-8,000 K
Which spectral type has the most prominent hydrogen absorption lines?
A) O
B) M
C) G
D) K
Answer: A) O
Which spectral type has the weakest hydrogen absorption lines?
A) O
B) M
C) G
D) K
Answer: M
What characteristic of a star’s spectrum provides information about its radial velocity?
A) Emission lines
B) Absorption lines
C) Continuum spectrum
D) Doppler shift
Answer: D) Doppler shift
What does the luminosity class Ia signify in stellar classification?
A) Main sequence
B) Giant
C) Supergiant
D) White dwarf
Answer: C) Supergiant
What is the luminosity class of a star that is still in the process of formation?
A) I
B) II
C) III
D) T Tauri
Answer: D) T Tauri
What is the luminosity class of a star that has exhausted its nuclear fuel and collapsed to a small size?
A) I
B) II
C) III
D) V
Answer: D) V
What is the luminosity class of a star that is transitioning off the main sequence?
A) I
B) II
C) III
D) IV
Answer: D) IV
Which luminosity class represents stars with the highest luminosity?
A) I
B) II
C) III
D) V
Answer: A) I
