Date: 202106
Flight conditions: VMC
Aircraft: Commercial Fixed Wing
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent; Initial Approach
Airspace: Class E ZLA
ATC / advisory: Center ZLA
Second aircraft: Sail Plane
Reporter organization: Air Carrier
Reporter function: Pilot Flying; First Officer
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Human factors: Time Pressure; Distraction; Situational Awareness
Second reporter function: Captain; Pilot Not Flying
Anomaly: Conflict NMAC
Detector: Automation Aircraft TA; Person Flight Crew
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Human Factors; Environment - Non Weather Related; Airspace Structure
Primary problem: Ambiguous

Narrative: Descending in to SNA on DSNEE 4 arrival between CARZZ and KADYN somewhere between 13;000-15;000 ft. we had a near miss with a glider. I was flying; never saw it. We got a primary target only; no mode C; 30 seconds or less from when the CA actually saw the glider; he guesses maybe 100 ft. vertically and 500 ft. laterally. The glider was right on the arrival path. It startled him; and even though I never saw it his reaction startled me. Great CRM; professionalism; training for us to get our focus back and not get distracted and become an unstable approach statistic in to the challenging SNA; especially after having hot brakes climbing out of ZZZ1 and having to lower the gear; it felt like a true multiple threat simulator session! Great scenario for an IOE.


Second narrative: Operating flight from ZZZ1 to SNA. Cleared to descend via the DSNEE 4 Arrival. Between CARZZ and KADYN Intersections at approximately 13;500 ft.; we received a 'Traffic; Traffic' TA with only a primary yellow circle popping up as a target with no altitude or trend information. The TA occurred about 20 seconds prior to us and the target converged. Center called 'traffic at 12 o'clock; altitude and type unknown'. The weather was VFR; but it was hazy. We scanned the immediate area above and below and did not see it.Then I looked to my left and I saw a white colored glider passing less than 500 ft. laterally and within 100 ft. vertically. I did not pick it up until it was at our 8 o'clock position and as we were descending on the arrival. We must have NEARLY HIT HIM! He was heading southeast bound.This occurrence made the hair stand up on my neck and it really shook me up. Just as I reported the near mid-air; ATC gave us a frequency change to Approach. I was so taken-aback by what had just happened; I had to ask Center to repeat the frequency. Just as I was trying to re-establish contact with Approach; I heard Approach calling us on Guard; which I thought was strange as we had only been off of Approach for less than 30 seconds. There seemed to be either a late hand-off from Center and they were looking for us; or they saw the near miss and were trying to call us. I mentioned that we had just missed a glider and we were trying to regain our composure but we had switched over in a fairly timely manner.After a busy; but uneventful approach and landing to 20R at SNA; during the taxi-in to Gate XX; SNA Ground alerted us that Approach was requesting that we call them once we parked.I called and spoke to a Supervisor. His first question was am I going to file a NASA report. I stated that I would. He took my name and number in the event that this occurrence needed further investigation. That glider was sailing on the main ridge-line just prior to entering the area. HE HAD NO MODE C transponder at an altitude that should have required him to have it. The glider was sailing on the direct arrival path of the STAR; and we are lucky that we hadn't arrived at our point of convergence 10 seconds sooner. When I saw him he was about 100 ft. higher than us at 8 o'clock as we were descending.


Synopsis: Flight crew reported a NMAC with a glider while they were on a STAR inbound to SNA.