A LEAR 45 FLC PERFORMS A LOW SPD ABORT AFTER REALIZING THAT THEY HAD LINED UP WITH THE R SIDE RWY LIGHTS FOR RWY 31C DURING THE TKOF ROLL; BELIEVING THEM TO BE THE CTRLINE LIGHTS AT MDW; IL.

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WE TAXIED TO RWY 31C AT MDW AND HELD SHORT OF THE RWY ON THE W SIDE. A B737 LANDED; AND WE WERE INSTRUCTED TO; 'TAXI INTO POS AND HOLD.' THERE WAS ANOTHER ACFT HOLDING SHORT OF RWY 31C OPPOSITE OF US. THE CAPT HAD THE TAXI LIGHTS OFF AS A COURTESY TO THE OPPOSITE AIRPLANE FACING US. HE LEFT THE LIGHTS OFF UNTIL WE HAD TURNED ON TO THE RWY APRON/DISPLACED THRESHOLD. THE CAPT LINED UP WITH WHAT HE THOUGHT WAS THE RWY CTRLINE LIGHTS. WE WERE GIVEN CLRNC TO TAKE OFF RWY 31C. THE CAPT ADVANCED THE PWR LEVERS AND THE ACFT BEGAN TO ACCELERATE. AS WE BEGAN TO MOVE FORWARD; CLOSER TO WHAT WE THOUGHT WERE CTRLINE LIGHTS; I NOTICED THAT THE LIGHTS WERE ACTUALLY THE RWY EDGE LIGHTS; STICKING OUT OF THE GND. I YELLED; 'LEFT' TO URGE THE CAPT TO MANEUVER THE AIRPLANE AWAY FROM THE R SIDE OF THE RWY. THE PLANE SWERVED TO THE L AND THE LIGHTS WERE PASSED AND WE REMAINED ON THE RWY. AT THE SAME TIME; THE CAPT REDUCED PWR TO IDLE AND CAME TO A STOP. I CALLED TWR OVER THE RADIO AND RPTED AN ABORTED TKOF. WE THEN TAXIED CLR OF THE ACTIVE RWY. AFTER WE WERE CLR OF THE RWY; TWR ASKED WHAT OUR INTENTIONS WERE. BOTH OF US WERE SURE THAT WE DID NOT HIT ANYTHING; BUT I SUGGESTED THAT WE TAXI BACK TO THE FBO AND VISUALLY INSPECT THE ACFT TO BE CERTAIN. WE TAXIED BACK TO THE FBO WHERE I GOT OUT OF THE AIRPLANE TO LOOK AT THE R SIDE OF THE AIRPLANE. I CAREFULLY INSPECTED THE R WING; R TIRES; R WHEELWELL; AND THE R WHEEL ASSEMBLY. THERE WAS NO EVIDENCE OF ANY DAMAGE. I GOT BACK INTO THE AIRPLANE AND TOLD THE CAPT. WE DECIDED WE WOULD TAXI BACK OUT FOR TKOF. I THINK THERE WERE A FEW FACTORS THAT LED TO MISALIGNMENT WITH THE RWY. I THINK THAT DUE TO THE SIZE AND LIGHTING THE RWY 31C'S APRON/DISPLACED THRESHOLD AREA; IT IS EASY TO MISTAKE THE R SIDE EDGE LIGHT WITH THE CTRLINE LIGHTING THAT YOU SEE AT MANY ARPTS. COMBINED WITH THE FACT THAT THE CAPT HAD THE TAXI LIGHTS OFF; WE PROBABLY THOUGHT THAT THE SPACE TO OUR R WAS THE R SIDE OF THE RWY. WE HAD ALSO BEEN ON DUTY AT THIS TIME FOR OVER 9 HRS. I THINK FATIGUE WITH ALL OF THE OTHER FACTORS LED TO MISALIGNMENT WITH THE RWY. EVEN WHEN WE LINED UP FOR TKOF THE SECOND TIME AND PAID SPECIAL ATTN TO OUR POS ON THE RWY; IT WAS STILL EVIDENT HOW SOMEONE COULD HAVE MISINTERPRETED THE RWY ALIGNMENT. SUPPLEMENTAL INFO FROM ACN 537818: THE TKOF WAS ABORTED FROM A SPD OF LESS THAN APPROX 20 KTS. WE HELD OFF WITH TURNING ON OUR LIGHTS AS NOT TO BLIND ANOTHER ACFT HOLDING SHORT ON THE OTHER SIDE. DOING THIS; WE MAY HAVE MISSED A TAXI LINE THAT GOES FROM THE HOLD SHORT POINT TO RWY CTR. BOTH PLTS HAD DISMISSED AN 'ODD FEELING' OF THIS BEING A WIDE RWY OR 'A SOMETHING DIFFERENT FEELING.' ABOUT THE TIME WE TURNED TO LINE UP; THE PNF REMARKED 'THERE'S CTRLINE' (ACTUALLY RWY EDGE MARKINGS) AND THE TWR CLRED US FOR TKOF. POOR LIGHTING OR MARKING/LIGHTING FOR THE RWY. THE R EDGE LIGHTS MAY APPEAR FURTHER UP THE RWY MAKING YOU THINK THAT'S CTRLINE.