Comprehensive wide-band magnitudes and albedos for the planets, with applications to exo-planets and Planet Nine

Abstract

Complete sets of reference magnitudes in all 7 Johnson-Cousins bands (U, B, V, R, I, R C and I C ) and the 5 principal Sloan bands (u', g', r', i', and z') o where a planet is near the greatest apparent separation from its star. This quantity may be useful in exo-planet detection and observation strategies when an estimate of the signal-to-noise ratio is needed. Likewise, the phase curves presented in this paper can be used for characterizing exo-planets. Finally, magnitudes for the proposed Planet Nine are estimated, and we note that P9 may be especially faint at red and near-IR wavelengths.

Two Planets Straddling the Habitable Zone of the Nearby K Dwarf Gl 414A

“…We predict that if its orbit is viewed close to 3.60 R ⊕ . Assuming that the bond albedo of planet b is equal to the mean total albedo of super-Earths (A t =0.32; Demory 2014) and planet cʼs albedo is equal to that of Saturn (A t =0.343; Mallama et al 2017), we calculate predicted equilibrium temperatures of T eq,b = 308.6±33.5 K and T eq,c = 124.7±13.5 K for these two planets. We list the full set of derived properties for each planet in Table 3.…”

Two Planets Straddling the Habitable Zone of The Nearby K Dwarf Gl 414A

“…We predict that if its orbit is viewed close to edge-on, planet b should have a radius of R b = 28.78 +4.03 −2.66 R ⊕ and planet c should have a radius of R c = 8.78 +4.03 −2.66 R ⊕ . Assuming the bond albedo of planet b is equal to the mean total albedo of super-Earths (A t = 0.32, Demory 2014) and planet c is equal to that of Saturn (A t = 0.343, Mallama et al 2017), we calculate predicted equilibrium temperatures of T eq,b = 303.7 ± 32.5 K and T eq,c = 123.3 ± 13.2 K for these two planets. We list the full set of derived properties for each planet in Table 3.…”

A search for Planet 9 in the IRAS data

“…It would clearly be desirable to reconsider the ephemerides limits for an object with this orbit. The best dataset for this search is the Panstarrs '3 π' survey in bands g,r,i,z,y of the entire sky north of dec = 14.3722 71.6913 0, 0, 0, 0, 0, 2.49 0, 0, 0, 3.1, 0 2.9, 0 0, 0, 0, 0, 0 1983 Sept 20 5.7hrs 13.7554 71.8560 0,0, 2.2, 0 0, 0, 0, 0, 0, 0 0, 0, 0, 0 Mallama et al (2017) give predicted colours and magnitudes for solar system planets, and we can use these to estimate colours and magnitudes for Neptune, Jupiter or Pluto -like objects, scaled for r=3.66 RE at a distance 225 AU , with an uncertainty of ± 0.3 dex in distance and radius. For Jupiter-like colours, (g,r,i,z = 16.84, 16.26, 16.41, 16.73), for Neptune-like colours, (g, r, i, z = 16.79, 16.95, 18.04, 18.90), and for Pluto-like colours, (g, r, i, z = 18.02.…”