Answer each of the following questions, include a brief explanation with each an

Question

Answer each of the following questions, include a brief explanation with each answer. a) Which star appear brightest in our sky? b) Which start appears faintest in our sky? c) Which start has the greatest luminosity? d) Which start has the least luminosity? e) Which star has the highest surface temperature? f) Which star has the lowest surface temperature? g) Which start is most similar to the Sun? h) Which star is a red supergiant? i) Which star has the largest radius? j) Among the main sequence-stars listed, which one is the most massive? k) Among the main-sequence stars listed, which one has the longest lifetime?

Explanation / Answer

a)

Sirius appear brightest in our sky.

Since it has the least apparent magnitude -1.4

b)

Regulus appears faintest in our sky.

since it has the greatest apparent magnitude +1.4

c)

Antares has the greatest luminosity.

Since it has the least absolute magnitude -4.5 Highly luminous stas have negative absolute magnitudes.

d)

Alpha centauri has the least luminosity.

Since it has the greatest absolute magnitude +4.4 . Less luminous stars have positive absolute magnitudes.

e)

Spica has highest surface temperature.

since its spectral type is B1 ( range of temperature for B spectral type is 10,000 K to 30,000 K )

f)

Antares has the least surface temperature.

Since its spectral type is M1 ( range of temperature for M spectral type is <3500 K)

g)

Alpha centauri is most similar to sun ,

Sun and Alpha centauri belong to same spectral type G2, and the absolute magnitude of sun is +4.83 which is nearly equal to absolute magnitude of Alpha centauri +4.4.

h)

Antares is red supergiant.

Since its spectral type is M ( stars belong to M spectral type are red stars)

i)

Antares is the star with largest radius.

since it has greatest luminosity, raius is directly proportional to square root of luminosity.

j)

Antares is most massive star

Since the luminisoty of Antares is greatest, it is more massive.

h)

Alpha centauri ( 5-6 billion years old)

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.