claim: The Raven (2012 film) is unreleased.
evidence: A technetium star , or more properly a Tc-rich star , is a star whose stellar spectrum contains absorption lines of the light radioactive metal technetium .. star. star. stellar spectrum. star spectrum. radioactive. radioactive. metal. metal. technetium. technetium. The most stable isotope of technetium is 98Tc with a half-life of 4.2 million years , which is too short a time to allow the metal to be material from before the star 's formation .. star. star. metal. metal. technetium. technetium. isotope. isotope. half-life. half-life. Therefore , the detection in 1952 of technetium in stellar spectra provided unambiguous proof of nucleosynthesis in stars , one of the more extreme cases being R Geminorum .. technetium. technetium. nucleosynthesis in stars. stellar nucleosynthesis. R Geminorum. R Geminorum. Stars containing technetium belong to the class of asymptotic giant branch stars -LRB- AGB -RRB- -- stars that are like red giants , but with a slightly higher luminosity , and which burn hydrogen in an inner shell .. technetium. technetium. asymptotic giant branch. asymptotic giant branch. red giants. red giants. luminosity. luminosity. hydrogen. hydrogen. Members of this class of stars switch to helium shell burning with an interval of some 100,000 years , in `` dredge-ups '' .. helium. helium. Technetium stars belong to the classes M , MS , S , SC and C-N .. Stellar classification#Class M. S-type star. C-N. Carbon star. They are most often variable stars of the long period variable types .. variable. variable star. long period variable. long period variable. Current research indicate that the presence of technetium in AGB stars occurs after some evolution , and that a significant number of these stars do not exhibit the metal in their spectra .. metal. metal. technetium. technetium. The presence of technetium seems to be related to the `` third dredge-up '' in the history of the stars .. technetium. technetium. dredge-up. dredge-up