Education

This section provides a carefully curated collection of essential resources specifically designed to assist students in the field of astronomy. These resources are intended to support academic learning and practical applications by offering critical information and tools. Topics include key concepts such as physical constants, measurement units, astronomical systems, and observational techniques.

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 (m_e): 9.1093897 × 10^-28 g
Electron charge (e): 4.8032068 × 10^-10 esu
Mass of proton (m_p): 1.672623 × 10^-24 g
Stefan-Boltzmann constant (σ): 5.67 × 10^-5 erg s^-1 cm^-2 deg^-4

Solar Constants

M = 1.989 × 10³³ g
R = 6.9599 × 10¹⁰ cm
Sp. type: G2V
T_eff = 5770 K
L = 3.826 × 10³³ erg/s
1 AU = 1.49598 × 10¹³ cm
M_v = +4.83

Unit Conversions

1 keV = 1.602177 × 10^-9 erg
1 keV = 2.417965 × 10¹⁷ Hz
1 keV = 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 F_i = -0.4 (M_i + M₀), where F_i (erg cm^-2 s^-1 Hz^-1)
zero-points M₀ for Johnson-Cousins system:
M_U = 49.30; M_B = 48.49; M_V = 48.61; M_R = 48.80; M_I = 49.06.

log F_i = -0.4 (M_i + M₀), where F_i (erg cm^-2 s^-1 Å^-1)
zero-points M₀ for Johnson-Cousins system:
M_U = 20.921; M_B = 20.521; M_V = 21.109; M_R = 21.609; M_I = 22.387.

SDSS: M_u = 22.798; M_g = 21.549; M_r = 22.232; M_i = 22.765.
HJK: M_H = 23.000; M_J = 24.848; M_K = 25.956.

I_ν (erg cm^-2 s^-1 Hz^-1) = 3.33 × 10^-19 λ²(Å) I_λ (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	λ_pivot (nm)	Nstd	Filter Zero Points	Vega STIS 005 Mag	0-Mag F_ν (Jy)	BandPass
B_T	419.6	7	-0.108 ± 0.045	-0.11	0.046	3821
V_T	530.6	5	-0.030 ± 0.020	-0.03	0.016	3689
U_L	354.6	13	0.761 ± 0.038	+0.76	0.005	1609
B_L	432.6	17	-0.103 ± 0.076	-0.10	-0.004	3979
V_L	544.5	17	-0.014 ± 0.021	-0.01	0.013	3646
R_L	652.9	14	0.154 ± 0.039	+0.15	0.040	3079
I_L	810.4	14	0.405 ± 0.066	+0.40	0.050	2520
U_M	358.9	13	0.763 ± 0.027	+0.76	0.005	1748
U_S	364.6	13	0.770 ± 0.050	+0.77	-0.050	1830
B_M	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
V_M	547.9	17	-0.014 ± 0.010	-0.01	0.019	3626
R_C	658.7	14	0.165 ± 0.014	+0.17	0.023	3066
I_C	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
Z_V	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
J_MK	1238.8	4	0.936 ± 0.020	+0.94	-0.027	1570
K_MK	2200.0	5	1.851 ± 0.038	+1.85	+0.017	663.0