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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

3168 results found.

  1. GRB 261029A: FRAM-ORM and FRAM-Auger optical afterglow light curve
  2. GRB 261029B : AstroSat CZTI detection
  3. GRB 261029A : AstroSat CZTI detection
  4. GRB 261028B / MAXI J1609-487: MAXI GSC detection
  5. GRB 261026B: AstroSat CZTI detection
  6. GRB 261024D: AstroSat CZTI detection of a long burst
  7. GRB 261024C: AstroSat CZTI detection of a long burst
  8. Fermi GRB 261026B: Global MASTER-Net observations report
  9. GRB 261026B: Fermi GBM Final Real-time Localization
  10. EP 261025a: COLIBRÍ optical upper limit
  11. GRB 261020B: AstroSat CZTI detection of a short burst
  12. GRB 261020A: MAXI GSC detection
  13. EP261015c: J-band upper limit with WINTER
  14. EP261006a : MeerKAT radio observations.
  15. MAXI GRB261012.23: Global MASTER-Net observations report
  16. EP261007b: Global MASTER-Net observations report
  17. GRB 261011A: Swift detection of an unusual burst
  18. EP261006a / AT 2026aetp: Multiband optical follow-up with the PKU 60cm Telescope
  19. GRB 261007A: SVOM/ECLAIRs refined analysis
  20. GRB 261007A / EP261007a: AstroSat CZTI detection
  21. GRB 261007A: Autonomous identification and follow-up of the counterpart to GRB 261007A by BTSbot with ZTF and P60/SEDM
  22. SVOM GRB261007.23: Global MASTER-Net observations report
  23. EP261006a: NOT spectroscopy of a blue continuum
  24. GRB 261007A: SVOM detection of a burst
  25. GRB 261001A: GECAM-B observation of a likely long GRB
  26. EP trigger 01709320908: Ondrejov D50 observation, fading star suggests stellar flare
  27. GRB 261003A: Fermi GBM Final Real-time Localization
  28. EP Alert 261003.01: Global MASTER-Net observations report
  29. GRB 260926C: AstroSat CZTI detection
  30. EP260924a: Global MASTER-Net observations report
  31. Fermi GRB 260926C: Global MASTER-Net observations report
  32. Swift Trigger 1513439 is probably not a GRB
  33. GRB 260924A: Optical follow-up observations with Kinder
  34. GRB 260924A: AstroSat CZTI detection
  35. Fermi GRB 260923A: Global MASTER-Net observations report
  36. GRB 260917C: AstroSat CZTI detection
  37. GRB 260921A: AstroSat CZTI detection
  38. EP260920b: VLT/X-shooter spectroscopic redshift z = 3.582
  39. GRB 260920A: AstroSat CZTI detection
  40. EP260920b: LCO optical counterpart detection
  41. EP Alert 260921.01: Global MASTER-Net observations report
  42. EP260917a: Global MASTER-Net observations report
  43. EP Alert 260918.24: Global MASTER-Net observations report
  44. SVOM GRB260918.16: Global MASTER-Net observations report
  45. Konus-Wind detection of GRB 260916B (short/hard)
  46. IPN triangulation of GRB 260916B (short)
  47. IceCube-260916A: Upper limits from a search for additional neutrino events in IceCube
  48. GRB 260915A: SVOM/ECLAIRs refined analysis
  49. MAXI GRB260916.37: Global MASTER-Net observations report
  50. GRB 260915A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  51. GRB 260915A: LCO optical upper limits
  52. EP Alert 260914.53: Global MASTER-Net observations report
  53. GRB 260915A: SVOM detection of a burst
  54. GRB 260914A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
  55. SVOM GRB260914.47: Global MASTER-Net observations report
  56. GRB 260910B: GOTO tentative optical counterpart candidates
  57. GRB 260910B: Fermi GBM Final Real-time Localization
  58. EP Alert 260909.53: Global MASTER-Net observations report
  59. Fermi GRB 260907A: Global MASTER-Net observations report
  60. GRB260903A: Liverpool Telescope optical observations
  61. GRB 260903A: SVOM/VT optical candidate
  62. EP260901a: Global MASTER-Net observations report
  63. GRB 260829A: AstroSat CZTI detection
  64. GRB 260827A: Glowbug gamma-ray detection
  65. GRB 260825A: AstroSat CZTI detection
  66. GRB 260827A: Fermi GBM Final Real-time Localization
  67. IceCube Alert 260825A: Global MASTER-Net observations report
  68. The EP-WXT trigger 01709287395 is likely a flaring star
  69. EP260806a: SVOM/ECLAIRs detection through targeted search
  70. EP260806a: NUTTELA-TAO optical observations
  71. GRB 260810A: AstroSat CZTI detection of a long burst
  72. GRB 260808A: BALROG localization (Fermi Trigger 807850307 / GRB 260808119)
  73. GRB 260808A: Fermi GBM Final Real-time Localization
  74. SN 2026stf / GRB 260708A: ATLAS forced photometry
  75. GRB 260803A: Fermi GBM Final Real-time Localization
  76. GRB 260802A/EP J223759.5+531421: SVOM detection of a possible magnetar burst
  77. GRB 260731A: AstroSat CZTI detection of a long burst
  78. GRB 260730B: AstroSat CZTI detection
  79. GRB 260727A: AstroSat CZTI detection
  80. Fermi GRB 260726A: Global MASTER-Net observations report
  81. GRB 260723A: Fermi GBM Final Localization
  82. GRB 260718A: SVOM/VT optical upper limits
  83. SVOM sb26071506: Global MASTER-Net observations report
  84. GRB 260710A: AstroSat CZTI detection
  85. GRB 260709A: AstroSat CZTI detection
  86. GRB 260714B: AstroSat CZTI detection
  87. GRB 260714B: Fermi GBM Final Real-time Localization
  88. GRB 260708A: GRANDMA Optical Observations
  89. GRB 260705C: AstroSat CZTI detection
  90. Fermi LAT GRB 260708A: MASTER OT J150237.02-435307.7 optical counterpart detection
  91. LAT GRB260708.42: Global MASTER-Net observations report
  92. GRB 260706A: SVOM/VT optical upper limits
  93. GRB 260705A: Candidate Optical Counterpart from SOAR and Gemini-South and Possible Association with GRB 260705B
  94. GRB 260707A: Fermi GBM Final Real-time Localization
  95. IPN triangulation of GRB 260627A
  96. GRB 260629A: AstroSat CZTI detection
  97. GRB 260610B / AT2026owq: SAO RAS, CrAO and INASAN further optical observations and light curve
  98. Fermi trigger No 804552016: Global MASTER-Net observations report
  99. GRB 260616B: AstroSat CZTI detection
  100. GRB 260616A: AstroSat CZTI detection

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