An observer uses the B and V filters to obtain four exposures of the same field atdifferent air masses: two B exposures at air masses 1.05 and 2.13, and two Vexposures at air masses 1.10 and 2.48. Four stars in this field are photometricstandards. Their standard magnitudes are given in the table below, as are the instru-mental magnitudes in each frame. Air mass Star A Star B Star C Star D (B−U)−0.070.360.691.15V12.0112.4412.1912.89b(1)1.059.85310.69310.75911.898b(2)2.1310.68711.47911.46212.547v(1)1.108.7789.1608.8739.522v(2)2.489.4279.7399.4255910.002(a) Compute the extinction coefficients for the instrumental system: kb′,kb′′,kv′, and kv′′ Hint: at each air mass, Equation (10.10) holds. Write an equation for the difference between the magnitudes at the two air masses (e.g. an equation for b(2)− b(1) ). Examination of this equation will suggest a method for computing the coefficients. You may find it helpful to enter the data from the table into a spreadsheet in performing the computations.(b) Compute the instrumental magnitudes of each star at zero air mass(c) Compute the transformation coefficients, αV,αB−V,βB−V, and γB−V, using themethod outlined in Section 10.7

Question

An observer uses the B and V filters to obtain four exposures of the same field atdifferent air masses: two B exposures at air masses 1.05 and 2.13, and two Vexposures at air masses 1.10 and 2.48. Four stars in this field are photometricstandards. Their standard magnitudes are given in the table below, as are the instru-mental magnitudes in each frame. Air mass  Star A  Star B  Star C  Star D ​(B−U)−0.070.360.691.15​V12.0112.4412.1912.89​b(1)1.059.85310.69310.75911.898​b(2)2.1310.68711.47911.46212.547​v(1)1.108.7789.1608.8739.522​v(2)2.489.4279.7399.4255910.002​​(a) Compute the extinction coefficients for the instrumental system: kb′​,kb′′​,kv′​, and kv′′​ Hint: at each air mass, Equation (10.10) holds. Write an equation for the difference between the magnitudes at the two air masses (e.g. an equation for b(2)− b(1) ). Examination of this equation will suggest a method for computing the coefficients. You may find it helpful to enter the data from the table into a spreadsheet in performing the computations.(b) Compute the instrumental magnitudes of each star at zero air mass(c) Compute the transformation coefficients, αV​,αB−V​,βB−V​, and γB−V​, using themethod outlined in Section 10.7

Filo · Accepted Answer

Click here to view the solution.

Question Text	An observer uses the $B$ and $V$ filters to obtain four exposures of the same field atdifferent air masses: two B exposures at air masses 1.05 and $2.13,$ and two $V$ exposures at air masses 1.10 and $2.48.$ Four stars in this field are photometricstandards. Their standard magnitudes are given in the table below, as are the instru-mental magnitudes in each frame. $Air mass Star A Star B Star C Star D (B - U) - 0.07 0.36 0.69 1.15 V 12.01 12.44 12.19 12.89 b (1) 1.05 9.853 10.693 10.759 11.898 b (2) 2.13 10.687 11.479 11.462 12.547 v (1) 1.10 8.778 9.160 8.873 9.522 v (2) 2.48 9.427 9.739 9.42559 10.002$ (a) Compute the extinction coefficients for the instrumental system: $k_{b}^{'}, k_{b}^{''}, k_{v}^{'},$ and $k_{v}^{''}$ Hint: at each air mass, Equation (10.10) holds. Write an equation for the difference between the magnitudes at the two air masses (e.g. an equation for $b (2) -$ $b (1)$ ). Examination of this equation will suggest a method for computing the coefficients. You may find it helpful to enter the data from the table into a spreadsheet in performing the computations.(b) Compute the instrumental magnitudes of each star at zero air mass(c) Compute the transformation coefficients, $α_{V}, α_{B - V}, β_{B - V},$ and $γ_{B - V},$ using themethod outlined in Section 10.7
Topic	All topics
Subject	Physics
Class	Class 12

Filo tutor solution

Practice more questions on All topics

Students who ask this question also asked