Strömgren photometric system

The following table shows the characteristics of each of the filters used (represented colors are only approximate):

Strömgren photometric system filter wavelength and half-width response functions

	u	v	b	y	βnarrow	βwide
Peak wavelength (nm)	350	411	467	547	485.8	485
Half-width (nm)	30	19	18	23	2.9	12.9

Note: colors are only approximate and based on wavelength to sRGB representation (when possible).[4]

There are four main highly applied and technical indices: ${\displaystyle (b-y)}$; ${\displaystyle m_{1}}$; ${\displaystyle c_{1}}$; and ${\displaystyle \beta }$.

• ${\displaystyle m_{1}=(v-b)-(b-y)}$
• ${\displaystyle c_{1}=(u-v)-(v-b)}$
• ${\displaystyle \beta =\beta _{narrow}-\beta _{wide}}$

Where;

• ${\displaystyle y}$ magnitudes are well-correlated with Johnson-Morgan V magnitudes (its V band).
• ${\displaystyle (b-y)}$ is sensitive to stellar temperature (measure of Paschen continuum).
• ${\displaystyle c_{1}}$ is sensitive to the surface gravity (measures Balmer discontinuity strength).
• ${\displaystyle m_{1}}$ is sensitive to the metallicity (measure of line blanketing).

• Photometric systems
• Stellar classification

• The Asiago Database on Photometric Systems
• The uvby photometric system
• Stromgren photometric system tutorial
• SAGA: Strömgren survey for Asteroseismology and Galactic Archaeology