Welcome, fellow astronomer. I am Ejnar Hertzsprung, from Denmark.  I demonstrated the existence of red giants and white dwarves. In 1913, the American astronomer Henry Russell and I independently published Hertzsprung-Russell diagrams of star types that included main-sequence, red-giant, blue and red super giant, and white dwarf stars.

I understand you've been studying about spectra.  That's very good preparation for astronomy, for several reasons.  A star's spectrum histogram-- or just spectrum for short--can tell us so many things about a star!  It can tell us what it is made of, how hot it is, how long it will live, and even about some of the processes that are going on inside it, or between the star and us! You will find out about all of this if you  continue to study astronomy.

I'm glad that you're here because I could use an assistant.  I am currently studying stars that emit extreme ultraviolet light. Saying "Extreme Ultraviolet" takes a lot of breath, so we say "EUV" instead.  I have observed a group of stars from all over the sky,  and made histograms of their spectra.  But I need to classify them into different types.

Take a look at the sky map on the Next page to see a map of my observation targets.