Astronomical & Physical Constants

Question 1

What is the solar mass (Mo)?

Answer 1

1.9891 × 10^30 kg

Represents the mass of the Sun

Question 2

What is the solar irradiance (S)?

Answer 2

1.365(2) x 10^3 W m^-2

Measure of solar power received per unit area

Question 3

What is the solar luminosity (Lo)?

Answer 3

3.839(5) × 10^26 W

Total amount of energy emitted by the Sun per second

Question 4

What is the solar radius (Ro)?

Answer 4

6.95508(26) × 10^8 m

Average distance from the center of the Sun to its surface

Question 5

What is the solar effective temperature (Te,o)?

Answer 5

5777(2) K

Temperature of a black body that would emit the same total amount of electromagnetic radiation

Question 6

What is the solar absolute bolometric magnitude (Mbol)?

Answer 6

4.74

Measure of the total brightness of the Sun

Question 7

What is the solar apparent bolometric magnitude (mbol)?

Answer 7

-26.83

Brightness of the Sun as seen from Earth

Question 8

What is the solar apparent ultraviolet magnitude (U)?

Answer 8

-25.91

Measure of brightness in the ultraviolet spectrum

Question 9

What is the solar apparent blue magnitude (B)?

Answer 9

-26.10

Brightness of the Sun in the blue spectrum

Question 10

What is the solar apparent visual magnitude (V)?

Answer 10

-26.75

Brightness of the Sun visible to the human eye

Question 11

What is the solar bolometric correction (BC)?

Answer 11

-0.08

Adjustment factor for the Sun’s bolometric magnitude

Question 12

What is the Earth mass (Mo)?

Answer 12

5.9736 × 10^24 kg

Mass of the Earth

Question 13

What is the Earth radius (equatorial) (Re)?

Answer 13

6.378136 × 10^6 m

Average radius of the Earth at the equator

Question 14

What is an astronomical unit (AU)?

Answer 14

1.4959787066 × 10^11 m

Average distance from Earth to the Sun

Question 15

What is the length of a light (Julian) year?

Answer 15

9.460730472 × 10^15 m

Distance light travels in one Julian year

Question 16

What is a parsec (pc)?

Answer 16

3.0856776 × 10^16 m

Unit of distance used in astronomy, equal to about 3.26 light years

Question 17

What is the length of a sidereal day?

Answer 17

23h56 04.09053095s

Time taken for the Earth to rotate once relative to the stars

Question 18

What is the length of a solar day?

Answer 18

86400 s

Standard 24-hour day based on the position of the Sun

Question 19

What is the length of a sidereal year?

Answer 19

365.256308 d

Time taken for the Earth to orbit the Sun relative to the stars

Question 20

What is the length of a tropical year?

Answer 20

365.2421897 d

Time taken for the Earth to complete one orbit around the Sun, measured from one vernal equinox to the next

Question 21

What is the length of a Julian year?

Answer 21

365.25 d

Average length of a year in the Julian calendar

Question 22

What is the length of a Gregorian year?

Answer 22

365.2425 d

Average length of a year in the Gregorian calendar

Question 23

The solar radius has an uncertainty of _______.

Answer 23

±0.00026 × 10^10 m

Indicates the precision of the solar radius measurement

Question 24

What is the gravitational constant (G)?

Answer 24

6.67428(67) × 10^-11 N m² kg^-2

Question 25

What is the speed of light (C)?

Answer 25

2.99792458 × 10^8 m s^-1

Question 26

What is the permeability of free space (μ₀)?

Answer 26

4π × 10^-7 N A^-2

Question 27

What is the permittivity of free space (ε₀)?

Answer 27

8.854187817 ... × 10^-12 F m^-1

Question 28

What is the electric charge (e)?

Answer 28

1.602176487(40) × 10^-19 C

Question 29

What is an electron volt (eV)?

Answer 29

1 eV = 1.602176487(40) × 10^-19 J

Question 30

What is Planck's constant (h)?

Answer 30

6.62606896(33) × 10^-34 J s

Question 31

What is Planck's constant multiplied by the speed of light (hc)?

Answer 31

1.23984187(3) × 10^3 eV nm ## Footnote ~ 1240 eV nm

Question 32

What is Boltzmann's constant (k)?

Answer 32

1.3806504(24) × 10^-23 J K^-1

Question 33

What is the Stefan-Boltzmann constant (σ)?

Answer 33

5.670400(40) × 10^-8 W m^-2 K^-4

Question 34

What is the radiation constant (R)?

Answer 34

7.565767(54) × 10^-16 J m^-3 K^-4

Question 35

What is the atomic mass unit (u)?

Answer 35

1.660538782(83) × 10^-27 kg

Question 36

What is the mass of an electron (mₑ)?

Answer 36

9.10938215(45) × 10^-31 kg

Question 37

What is the mass of a proton (mₚ)?

Answer 37

1.672621637(83) × 10^-27 kg

Question 38

What is the mass of a neutron (mₙ)?

Answer 38

1.67592711(84) × 10^-27 kg

Question 39

What is the mass of hydrogen (mₕ)?

Answer 39

1.673532499(13) × 10^-27 kg

Question 40

What is Avogadro's number (Nₐ)?

Answer 40

6.02214179(30) × 10^23 mol^-1

Question 41

What is the gas constant (R)?

Answer 41

8.314472(15) J mol^-1 K^-1

Question 42

What is the Bohr radius (a₀)?

Answer 42

5.2917720859(36) × 10^-11 m

Question 43

What is the Rydberg constant (Rₕ)?

Answer 43

1.0973731568527(73) × 10^7 m^-1