Physical and Solar Constants
Fundamental Physical Constants
- Speed of light in vacuum (c): 2.99792458 × 1010 cm/s
- Gravitation constant (G): 6.67259 × 10-8 dyn cm2 g-2
- Planck's constant (h): 6.626075 × 10-27 erg s
- Boltzmann constant (k): 1.38066 × 10-16 erg/K
- Mass of electron (me): 9.1093897 × 10-28 g
- Electron charge (e): 4.8032068 × 10-10 esu
- Mass of proton (mp): 1.672623 × 10-24 g
- Stefan-Boltzmann constant (σ): 5.67 × 10-5 erg s-1 cm-2 deg-4
Solar Constants
- Mass: 1.989 × 1033 g
- Radius: 6.9599 × 1010 cm
- Spectral type: G2V
- Effective temperature: 5770 K
- Luminosity: 3.826 × 1033 erg/s
- 1 AU: 1.49598 × 1013 cm
- Mv: +4.83
Unit Conversions
- 1 keV = 1.602177 × 10-9 erg
- 1 keV = 2.417965 × 1017 Hz = 12.3985 Å = 11.6048 × 106 K
- 1018 Hz = 4.13571 keV
- 1 Å = 10-8 cm
- 1 μJy = 10-29 erg cm-2 s-1 Hz-1
- 1 pc = 3.086 × 1018 cm
Frequency-Wavelength Conversion
- 3 × 108 Hz = 300 MHz = 1 m (radio)
- 3 × 1011 Hz = 300 GHz = 1 mm (microwave)
- 3 × 1014 Hz = 300 THz = 1 μm (IR/optical/UV)
- 3 × 1017 Hz = 300 PHz = 1 nm (X-rays)
- 3 × 1020 Hz = 30 EHz = 1 pm (γ-rays)
Astronomical Magnitude System
log Fi = -0.4 (Mi + M0), where Fi (erg cm-2 s-1 Hz-1)
zero-points M0 for Johnson-Cousins system:
MU = 49.30; MB = 48.49; MV = 48.61; MR = 48.80; MI = 49.06.
log Fi = -0.4 (Mi + M0), where Fi (erg cm-2 s-1 Å-1)
zero-points M0 for Johnson-Cousins system:
MU = 20.921; MB = 20.521; MV = 21.109; MR = 21.609; MI = 22.387.
SDSS: Mu = 22.798; Mg = 21.549; Mr = 22.232; Mi = 22.765.
HJK: MH = 23.000; MJ = 24.848; MK = 25.956.
Iν (erg cm-2 s-1 Hz-1) = 3.33 × 10-19 λ2(Å) Iλ (erg cm-2 s-1 Å-1)
Johnson-Cousins Filters
| Filter | λ | Δλ | ν | Δν | log ν | A(λ)/A(V) | A(E(B-V)) |
|---|---|---|---|---|---|---|---|
| U | 3652 Å | 526 Å | 8.215e14 Hz | 1.19e14 Hz | 14.829 (0.059) | 1.664 | 5.434 |
| B | 4448 Å | 1008 Å | 6.744e14 Hz | 1.55e14 Hz | 14.829 (0.075) | 1.321 | 4.315 |
| V | 5505 Å | 827 Å | 5.456e14 Hz | 8.24e13 Hz | 14.736 (0.061) | 1.015 | 3.315 |
| Rc | 6588 Å | 1569 Å | 4.556e14 Hz | 1.01e14 Hz | 14.658 (0.087) | 0.819 | 2.673 |
| Ic | 8060 Å | 1542 Å | 3.720e14 Hz | 7.19e13 | 14.571 (0.077) | 0.594 | 1.940 |
JHK
| Filter | λ | Δλ | ν | Δν | log ν | A(λ)/A(V) | A(E(B-V)) |
|---|---|---|---|---|---|---|---|
| J | 12150 Å | 2600 Å | 2.471e14 Hz | 5.34e13 Hz | 14.393 (0.085) | 0.276 | 0.902 |
| H | 16540 Å | 2900 Å | 1.814e14 Hz | 3.24e13 Hz | 14.259 (0.071) | 0.176 | 0.576 |
| K | 21790 Å | 4100 Å | 1.380e14 Hz | 2.61e13 Hz | 14.140 (0.085) | 0.112 | 0.367 |
Zero Points, Zero-Mag Fluxes and Selected System/Filter Bandpasses
| Filter | λpivot (nm) | Nstd | Filter Zero Points | Vega STIS 005 Mag | 0-Mag Fν (Jy) | BandPass |
|---|---|---|---|---|---|---|
| BT | 419.6 | 7 | -0.108 ± 0.045 | -0.11 | 0.046 | 3821 |
| VT | 530.6 | 5 | -0.030 ± 0.020 | -0.03 | 0.016 | 3689 |
| UL | 354.6 | 13 | 0.761 ± 0.038 | +0.76 | 0.005 | 1609 |
| BL | 432.6 | 17 | -0.103 ± 0.076 | -0.10 | -0.004 | 3979 |
| VL | 544.5 | 17 | -0.014 ± 0.021 | -0.01 | 0.013 | 3646 |
| RL | 652.9 | 14 | 0.154 ± 0.039 | +0.15 | 0.040 | 3079 |
| IL | 810.4 | 14 | 0.405 ± 0.066 | +0.40 | 0.050 | 2520 |
| UM | 358.9 | 13 | 0.763 ± 0.027 | +0.76 | 0.005 | 1748 |
| US | 364.6 | 13 | 0.770 ± 0.050 | +0.77 | -0.050 | 1830 |
| BM | 437.2 | 17 | -0.116 ± 0.020 | -0.12 | 0.012 | 4003 |
| B3 | 440.2 | 17 | -0.124 ± 0.024 | -0.12 | 0.012 | 4050 |
| VM | 547.9 | 17 | -0.014 ± 0.010 | -0.01 | 0.019 | 3626 |
| RC | 658.7 | 14 | 0.165 ± 0.014 | +0.17 | 0.023 | 3066 |
| IC | 789.1 | 14 | 0.386 ± 0.016 | +0.39 | 0.031 | 2547 |
| J | 1239.0 | 15 | 0.913 ± 0.022 | +0.91 | -0.016 | 1601 |
| H | 1649.5 | 15 | 1.352 ± 0.024 | +1.35 | +0.018 | 1034 |
| K | 2163.8 | 15 | 1.830 ± 0.018 | +1.83 | +0.008 | 670.3 |
| ZV | 877.6 | 5 | 0.583 ± 0.038 | +0.58 | -0.069 | 2268 |
| Y | 1020.8 | 5 | 0.607 ± 0.031 | +0.61 | -0.021 | 2092 |
| JMK | 1238.8 | 4 | 0.936 ± 0.020 | +0.94 | -0.027 | 1570 |
| KMK | 2200.0 | 5 | 1.851 ± 0.038 | +1.85 | +0.017 | 663.0 |