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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.

Advanced Search Examples (click to copy):

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

1022 results found.

  1. GRB 260818B: LCO optical upper limits
  2. GRB 260818B: SVOM detection of a short burst
  3. GRB 260818A: LCO optical upper limits
  4. GRB 260818A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  5. GRB 260818A: SVOM possible detection of a long and faint GRB
  6. EP260806a: SVOM/ECLAIRs detection through targeted search
  7. GRB 260805D: SVOM/GRM detection of a possible magnetar burst
  8. EP260812a: SVOM/C-GFT optical upper limit
  9. EP260812b: SVOM/VT optical observation
  10. GRB 260808A: SVOM/GRM observation
  11. GRB 260808B: SVOM/COLIBRÍ (FM-GFT) confirmation of the optical rebrightening
  12. GRB 260808B: SVOM/VT optical re-brightening at day 3
  13. GRB 260317A: SVOM/ECLAIRs detection through offline targeted search and its possible association to magnetar 1E 1841-04.5
  14. GRB 260807A: SVOM/ECLAIRs refined analysis
  15. GRB 250607A: SVOM/ECLAIRs detection through offline targeted search
  16. GRB 260809A: SVOM/COLIBRÍ (FM-GFT) optical observation
  17. GRB 260808B: SVOM/COLIBRÍ (FM-GFT) optical observation
  18. GRB 260809A: SVOM/VT optical counterpart
  19. GRB 260808B: SVOM/ECLAIRs refined analysis
  20. GRB 260809A: SVOM detection of a faint burst
  21. GRB 260808B: LCO optical observations
  22. GRB 260808B: SVOM/VT optical afterglow confirmation
  23. GRB 260808B: SVOM/VT optical candidate from VHF data ( localization correction for GCN 45317 )
  24. GRB 260808B: SVOM/VT optical candidate from VHF data
  25. GRB 260808B: SVOM detection of a faint burst
  26. GRB 260807A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  27. GRB 260807A: SVOM possible detection of a faint burst
  28. EP260806a: SVOM/VT optical observation
  29. GRB 260708A: LCO further optical observations show supernova features
  30. GRB 260802A / EP J223759.5+531421: SVOM/VT optical upper limit
  31. GRB 260802A: SVOM/VT optical upper limits from VHF data
  32. GRB 260802A: LCO optical upper limits
  33. GRB 260802A / EP J223759.5+531421: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  34. GRB 260802A/EP J223759.5+531421: SVOM detection of a possible magnetar burst
  35. GRB 260727A: EP-FXT further follow-up observations and candidate afterglow
  36. GRB 260618B: SVOM/VT continued optical observations indicated a steeper and redder decay
  37. GRB 260727A: SVOM/ECLAIRs refined analysis
  38. GRB 260726A: SVOM/ECLAIRs refined analysis
  39. GRB 260726A: EP-FXT follow-up observations
  40. GRB 260727A: SVOM/GRM observation
  41. GRB 260727A: EP/FXT follow-up observations
  42. GRB 260726A: SVOM/VT optical candidate
  43. GRB 260726A: SVOM ECLAIRs improved position and MXT possible detection of a counterpart
  44. EP260723a: SVOM/ECLAIRs Upper Limit
  45. GRB 260727A: LCO optical upper limits
  46. GRB 260727A: SVOM detection of a bright long burst
  47. GRB 260726A: SVOM detection of a burst
  48. GRB 260718A: SVOM/ECLAIRs refined analysis
  49. EP260723a: SVOM/VT optical observation
  50. SVOM trigger sb26071506: SVOM/VT confirmation of a stellar flare
  51. GRB 260718A: LCO optical upper limits
  52. GRB 260711A: SVOM/GRM observation
  53. GRB 260710A: SVOM/GRM observation
  54. GRB 260718A: SVOM/VT optical upper limits
  55. GRB 260718A: SVOM/VT optical upper limits from VHF data
  56. GRB 260718A: SVOM detection of a burst
  57. GRB 260714B: SVOM/GRM observation
  58. sb26071506: SVOM detection of a X-ray transient
  59. EP260703a: SVOM/ECLAIRs Upper Limit
  60. GRB 260619A: SVOM/VT continuous optical observations
  61. GRB 260618B: SVOM/VT optical observations indicate shallow decay and reddening
  62. GRB 260708A: LCO optical observations
  63. GRB 260709A: SVOM/GRM detection
  64. GRB 260704A: SVOM/ECLAIRs refined analysis
  65. GRB 260705B: SVOM/GRM observation
  66. GRB 260706A: Further EP-FXT follow-up observation
  67. GRB 260706A: SVOM/VT optical upper limits
  68. GRB 260706A: SVOM/ECLAIRs refined analysis
  69. GRB 260704A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
  70. GRB 260706A: SVOM/GRM observation
  71. GRB 260706A: LCO optical upper limit
  72. GRB 260705A: SVOM/ECLAIRs refined analysis
  73. GRB 260706A: SVOM detection of a burst
  74. GRB 260705A: LCO optical upper limits
  75. GRB 260705A: SVOM detection of a burst
  76. GRB 260629A: SVOM/GRM observation of a short burst
  77. GRB 260704A: SVOM detection of a possible GRB
  78. GRB 260619A: SVOM/ECLAIRs refined analysis
  79. EP260623a: SVOM/VT optical observations
  80. GRB 260614B: EP-FXT follow-up observation
  81. GRB 260618C: SVOM/ECLAIRs detection of a possible burst through on-ground search
  82. GRB 260618B: LCO optical observations
  83. GRB 260616B/EP260616a: SVOM/GRM detection of a burst
  84. GRB 260619A: SVOM/VT optical counterpart confirmation
  85. GRB 260618B: SVOM/VT optical candidate
  86. GRB 260618B: SVOM/VT optical candidate (duplicate Submission of 45001)
  87. GRB 260619A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  88. GRB 260616A: SVOM/GRM observation
  89. GRB 260619A: SVOM possible detection of a faint burst
  90. GRB 260614B: SVOM/ECLAIRs refined analysis
  91. GRB 260610B: SVOM/GRM observation
  92. GRB 260614B: SVOM/VT optical afterglow confirmation
  93. GRB 260614B: SVOM/VT optical candidate from VHF data
  94. GRB 260614B: SVOM detection of a burst
  95. GRB 260611B: SVOM/GRM detection
  96. The EP-WXT trigger 01709269176: SVOM/C-GFT confirmation of a stellar flare
  97. GRB 260610B / AT2026owq: SVOM/VT optical observations
  98. EP260610b: SVOM/VT optical confirmation with blue color
  99. EP260610a: SVOM/VT optical upper limits
  100. GRB 260604C: SVOM/ECLAIRs refined analysis

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