Good idea, Moonlady!
My question was too hard, so here is the answer.
The arachnid red (although really yellow) bright "heart" is Antares in Scorpius. It is one of only two bright-looking red (in reality yellow) supergiants in the sky! The other one is Betelgeuse in Orion.
The two "arteries" leading up to it, the near-twins of very similar spectral classes and very similar apparent magnitudes, the blue stars which share the same name, are Sigma Scorpius, magnitude 2.90, a double star whose components are spectral classes B1III + O9.5V, plus Tau Scorpii, magnitude 2.82, spectral class B0V. The Greek letters Sigma and Tau follow each other in the Greek alphabet, and Sigma Scorpius and Tau Scorpius share the same name, Al Niyat, which means "artery".
In the picture, Antares is the bright yellow star slightly below center. Sigma Scorpii is at 3 o'clock, surrounded by both blue and red nebulosity. Tau Scorpii is at 7 o'clock.
Ann
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(little-known) name! 
