What is the wavelength shift (delta) (h) of a exoplanetery system at a wavelength of X angstroms if an exoplan et creates a doppler shift in its star of 2.4 km per second? Use the doppler equation (delta)/(h) = v/c

Observations show that the gas ejected from SN 1987A is moving at about 10,000 km/s. How long will it take to travel one astronomical unit? One parsec? (Note that 1 AU equals 1.5 × 108 km, and 1 pc equals 3.1 × 10¹³ km.)

A planetary nebula expanded in radius 0.3 arc seconds in 30 years.  Doppler measurements show the nebula is expanding at a rate of 35 km/s.  How far away is the nebula in parsecs? First, determine what distance the nebular expanded in parsecs during the time mentioned.  Δd = vpc/sTs So we first need to convert the rate into pc/s and the time into seconds: vpc/s = vkm/s (1 pc / 3.09 x 1013km) vpc/s = ? Ts = (Tyr)(365 days/yr)(24 hrs/day)(3600 s/hr) Ts = ? s Δd= vpc/sTs Therefore, Δd = ? pc

For each problem, use the following values: c = 3x108 m/s mass of the sun = 1.989 x 1030 kg luminosity of the sun = 3.828 x 1026 W 1 AU = 1.496 x 1011 m 1 pc = 3.262 light years = 3.086 x 1016 m 1 year=3.154x107 seconds Critical density of our Universe (expressed as a mass density): Pcrit =8.7 x 10-27 kg m-³ Critical energy density of our Universe: Ecrit = Pcrit c² G=6.674 × 10-11 m³.kg-1.s-2 1 eV = 1.60218 x10-19. Boltzmann constant: kg = 1.381 x 10-23 JK-18.617 × 10-5eV K-1 energy density constant (in Stefan Boltzmann Law): a = 7.566 x 10-16 Jm-3 K-4 -4.7 x 10-³ MeV m-3 K-4 Constant in Wein displacement law: b = 2.898 x 10-3 m K baryon-to-photon ratio, n = 6 x 10-10

Assuming that at the end of the He burning phase of the stellar core (r < R_core) has no H or He or other metals and is composed completely of Carbon, X=Y=0, X_c = 1 ; The envelope above the core has a normal stellar composition ( r > R_core). Calculate the length of time in years that a 1M_sol and 10M_sol star will live on the horizontal branch or the time between the start and end of the He burning phase. Assume that the normal relationship between mass and luminosity holds for horizontal branch stars. Please be as detailed as possible

Calculate the angular diameter of a prestellar nebula of radius 125 AU lying 150 pc from Earth. angular diameter = 15. ΑΣΦ B ? arc seconds

Suppose that stars were born at random times over the last 10e10 years. The rate ofstar formation is simply the number of stars divided by 10e10 years. The fraction ofstars with detected extrasolar planets is at least 9 %. The rate of star formation can bemultiplied by this fraction to find the rate planet formation. How often (in years) doesa planetary system form in our galaxy? Assume the Milky Way contains 7 × 10e11 stars. I've done this problem 3 different times from scratch and looked at similar problems here. Each time my answer is 1.587 (1.59 rounded to 2 significant figures), but when I submit, it says the answer is wrong. What do you think?

Q. 3: The angular velocity of rotation of a star (of mass M and radius R) at which the matter from its equator is starts escape 2 GR 2 GM (a) (b) ^ R³ 2 GM 2 GM? 2000 (d) R

We observe a star that is dstar​ away.  How much extinction would there need to be (i.e., what must tau be) if we had ignored intervening dust, and concluded that it was actually 2 * dstar​ away? Value: dstar​ = 526 pc

White Dwarf Size II. The white dwarf, Sirius B, contains 0.98 solar mass, and its density is about 2 x 106 g/cm?. Find the radius of the white dwarf in km to three significant digits. (Hint: Density = mass/volume, and the volume of a 4 sphere is Tr.) 3 km Compare your answer with the radii of the planets listed in the Table A-10. Which planet is this white dwarf is closely equal to in size? I Table A-10 I Properties of the Planets ORBITAL PROPERTIES Semimajor Axis (a) Orbital Period (P) Average Orbital Velocity (km/s) Orbital Inclination Planet (AU) (106 km) (v) (days) Eccentricity to Ecliptic Mercury 0.387 57.9 0.241 88.0 47.9 0.206 7.0° Venus 0.723 108 0.615 224.7 35.0 0.007 3.4° Earth 1.00 150 1.00 365.3 29.8 0.017 Mars 1.52 228 1.88 687.0 24.1 0.093 1.8° Jupiter 5.20 779 11.9 4332 13.1 0.049 1.30 Saturn 9.58 1433 29.5 10,759 9.7 0.056 2.5° 30,799 60,190 Uranus 19.23 2877 84.3 6.8 0.044 0.8° Neptune * By definition. 30.10 4503 164.8 5.4 0.011 1.8° PHYSICAL PROPERTIES (Earth = e)…