Conversions to SI units

 

 

Table 4: Conversions from various units to SI units

M$_{\odot}$	$= 1.989 \times 10^{30}$ kg
u (a.m.u.)	$= 1.661 \times 10^{-27}$ kg
Mpc	$= 3.086 \times 10^{22}$ m
pc	$= 3.086 \times 10^{16}$ m
au	$= 1.496 \times 10^{11}$ m
R$_{\odot}$	$= 6.960 \times 10^{8}$ m
year	$= 3.156 \times 10^{7}$ s
day	$= 8.640 \times 10^{4}$ s
km s-1 Mpc-1	$=3.241 \times 10^{-20}$ s-1
degree	$= 1.745 \times 10^{-2}$ rad
arcsec	$= 4.848 \times 10^{-6}$ rad
erg	$= 1 \times 10^{-7}$ J
eV	$= 1.602 \times 10^{-19}$ J
L$_{\odot}$	$\approx 3.85 \times 10^{26}$ W
erg s-1 cm-2	$= 1 \times 10^{-3}$ W m-2
Jy	$= 1 \times 10^{-26}$ W m-2 Hz-1

 

 

Table 5: The electromagnetic spectrum: conversions

range	wavelength		frequency		photon energy
$\gamma$-ray
	12.4	fm	24200	EHz	100	MeV
$\gamma$-ray
	2.5	pm	121	EHz	500	keV
X-ray
	248	pm	1210	PHz	5	keV
X-ray
	12.4	nm	24	PHz	0.1	keV
XUV
	90	nm	3330	THz	13.8	eV
far UV
	180	nm	1670	THz	6.89	eV
mid UV
	300	nm	1000	THz	4.14	eV
near UV
	400	nm	750	THz	3.10	eV
visible
	750	nm	400	THz	1.65	eV
near IR
	1	$\mu{\rm m}$	300	THz	1.24	eV
near IR
	5	$\mu{\rm m}$	60	THz	0.25	eV
mid IR
	25	$\mu{\rm m}$	12	THz	49.6	meV
far IR
	100	$\mu{\rm m}$	3	THz	12.4	meV
far IR
	350	$\mu{\rm m}$	857	GHz	3.54	meV
sub-mm radio
	1	mm	300	GHz	1.24	meV
microwave radio
	30	mm	10	GHz	41.4	$\mu$eV
microwave radio
	1	m	300	MHz	1.24	$\mu$eV
radio
	60	m	5	MHz	20.7	neV
radio
	15	km	20	kHz	82.7	peV
radio

 

 

Table 6: SI prefixes

atto

femto

pico

nano

micro

milli

kilo

mega

giga

tera

peta

exa

a

f

p

n

$\mu$

m

k

M

G

T

P

E

10-18

10-15

10-12

10-9

10-6

10-3

103

106

109

1012

1015

1018