Step 1: Identify the event tied to Taregna.
Taregna, a small village near Patna in Bihar, made national news in July 2009 as a prime spot to view the total solar eclipse of that year.
Step 2: Note the historical connection.
The village holds cultural weight since it is linked to the ancient astronomer Aryabhata, which made it a favored viewing site for scientists and eclipse watchers.
Step 3: Rule out the other options.
No major Rahul Gandhi campaign event, Hillary Clinton visit, or Naxal attack was reported from Taregna around that period, so those choices do not match the news reason.
Final Answer:
Taregna was in the news for hosting viewing of the 2009 solar eclipse. \[ \boxed{\text{Solar eclipse viewing}} \]