Nothing is known of the life of "Cowboy Jim" Jonas prior to his appearance on the rodeo circuit in the late 1940's.  In the fall of 1948, he was traveling through the Northeast and performed with a troupe outside of Gotham City.  His performance was attended by Alan Scott and Doiby Dickles who speculate that Jonas' rope skills are so prodigious that he would make an excellent crime fighter.  Their convo is overhead and as they are walking home, thugs in a passing van accost them but throw bundles of stacked newspaper to knock them down.    Alan rolls out of sight to switch to his Green Lantern identity and after routing the men, finds that the newspaper has announced a new hero in Gotham - White Star!

Shortly thereafter, Green Lantern received a challenge from White Star to catch more of a gang of fur thieves that he could.  Green Lantern agreed not to compete but to collaborate with the new hero and when they arrived outside a warehouse, White Star stated that the crooks were inside looting the furs. Green Lantern blasted the wall open but found no crooks inside.  To the contrary the crooks were outside and ran in through the breach, with Green Lantern and White Star both taking fire.  White Star goaded Green Lantern as to who was the better crime-fighter but at the height of the fight with the thieves, White Star bumbled into him, allowing the crooks to club he and Doiby.  The crooks escaped with half the furs but White Star tells the press he was too busy, protecting Green Lantern to stop them.

In the aftermath, Green Lantern expresses his suspicions to Doiby that he finds White Star's accident a bit too convenient for the thieves. The next day, another newspaper ad solicits the attention of the Green Lantern, this time to the Midas Gold Refining Plant.  White Star arrives early and warns  the guards that  they are likely to be robbed by someone disguised as Green Lantern.  When the real Green Lantern arrives, he is beset by the guards disguised as his "gang".  Foiling  the deceit, Green Lantern and the guards race inside to find White Star and the gang from the fur robbery looting the gold.  After a quick melee, White Star drops on of his men on Green Lantern, stunning him long enough to escape.

Recovering, Green Lantern finds the White Star's lariat with a X emblazoned on the rope.  Returning to the radio, he interrupts Cowboy Jim's act and after capturing him, revealed that he had seen that same symbol at the rodeo, suggesting that White Star was in fact Jim Jonas.  A search of his trailer revealed the White Star's uniform and the stolen gold, confirming his identity and sending him off with the police (Green Lantern #34). 

The further activities of White Star are unrecorded.