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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"

19223 results found.

  1. GRB 260710A: Fermi GBM Detection
  2. GRB 260709A: SVOM/GRM detection
  3. GRB 260709A: GECAM-B observation
  4. The EP-WXT trigger 01709274666 is likely a new outburst of the CV SS Cyg
  5. IceCube-260708A: Observations with the Vera C. Rubin Observatory
  6. GRB 260705C: AstroSat CZTI detection
  7. GRB 260710A: Fermi GBM Final Real-time Localization
  8. GRB 260708A: Glowbug gamma-ray detection
  9. GRB 260704A: SVOM/ECLAIRs refined analysis
  10. GRB 260706A : GRANDMA Upper limits
  11. GRB 260708A: GECAM-B observation of a burst
  12. IceCube-260708A: One candidate from the Zwicky Transient Facility
  13. GRB 260708A: Fermi-GBM observation
  14. Fermi LAT GRB 260708A: MASTER OT J150237.02-435307.7 optical counterpart detection
  15. IceCube Alert 260709A: Global MASTER-Net observations report
  16. GRB 260709A: Fermi GBM Final Real-time Localization
  17. LAT GRB260708.42: Global MASTER-Net observations report
  18. GRB260708B: MAXI/GSC detection
  19. GRB 260708A: Fermi-LAT detection
  20. GRB 260705B: SVOM/GRM observation
  21. GRB 260708A: Fermi-GBM detection
  22. GRB 260706A: Further EP-FXT follow-up observation
  23. GRB 260706A: SVOM/VT optical upper limits
  24. EP260707a (by EP-FXT): NOT optical upper limit
  25. EP260707a: LCOGT Optical Upper Limit
  26. Fermi GBM trigger 805087514/260707142 (GRB 260707A) is not a GRB
  27. EP260707a: Einstein Probe detection of an X-ray transient
  28. Nova AT2026oyp (ASASSN-26dt): Pre-outburst Swift UVOT observation
  29. GRB 260705A: Candidate Optical Counterpart from SOAR and Gemini-South and Possible Association with GRB 260705B
  30. GRB 260705C: Glowbug gamma-ray detection of a short burst
  31. GRB 260706A: SVOM/ECLAIRs refined analysis
  32. GRB 260704A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
  33. GRB 260706A: SVOM/GRM observation
  34. GRB 260706A: REM optical/NIR observations
  35. IceCube-260704A: No candidates from the Zwicky Transient Facility
  36. GRB 260706A: LCO optical upper limit
  37. GRB 260706A: EP-FXT follow-up observation
  38. GRB 260707A: Fermi GBM Final Real-time Localization
  39. The EP-WXT trigger 01709274151 is likely a flaring star
  40. The EP-WXT trigger 01709274141 is likely a flaring star
  41. GRB 260706A: Fermi GBM Observation
  42. IceCube-260704A: Upper limits from a search for additional neutrino events in IceCube
  43. GRB 260706A: SVOM detection of a burst
  44. GRB 260706A: Fermi GBM Final Real-time Localization
  45. The EP-WXT trigger 01709274014 is likely a flaring star
  46. IceCube260704A: OHP/T193 optical observations
  47. GRB 260705A: LCO optical upper limits
  48. GRB 260704A: NOT optical upper limits
  49. GRB 260705C: Fermi GBM Final Localization
  50. GRB 260705B: Fermi GBM Final Real-time Localization
  51. Fermi GBM Sub-Threshold Detection of GRB 260705A
  52. GRB 260705A: SVOM detection of a burst
  53. GRB 260704A: EP-FXT follow-up observation
  54. GRB 260629A: SVOM/GRM observation of a short burst
  55. GRB 260629A: GECAM-A observation of a short burst
  56. GRB 260629A: AstroSat CZTI detection
  57. EP260703a: EP-FXT follow-up observation
  58. GRB 260704A: SVOM detection of a possible GRB
  59. GRB 260703B: Fermi GBM Final Localization
  60. EP260703a: EP-WXT detection of a fast X-ray transient
  61. EP260628b: EP-WXT detection of an X-ray transient and EP-FXT follow-up observation
  62. Fermi trigger No 804738310: Global MASTER-Net observations report
  63. Fermi GRB 260703A: Global MASTER-Net observations report
  64. GRB 260703A: Fermi GBM Final Localization
  65. GRB 260610B: VLA detection
  66. GRB 260623A: Glowbug gamma-ray detection
  67. GRB 260610B / AT2026owq: SAO RAS, CrAO and INASAN further optical observations and light curve
  68. Fermi trigger No 804552016: Global MASTER-Net observations report
  69. GRB 260701A: Fermi GBM Final Real-time Localization
  70. Fermi GBM trigger 804552016/260630945 is not a GRB
  71. Fermi-LAT Gamma-ray Observations of IceCube-260622A
  72. EP260628a: EP-FXT follow-up observation
  73. GRB 260629A: Fermi GBM Final Real-time Localization
  74. Fermi GRB 260628A: Global MASTER-Net observations report
  75. EP260628a: EP-WXT detection of a fast X-ray transient
  76. GRB 260628A: Fermi GBM Final Real-time Localization
  77. The EP-WXT trigger 01709272671 is likely a flaring star
  78. EP260626a: further Liverpool Telescope optical upper limits
  79. EP260626a: COLIBRÍ optical upper limit
  80. EP260626a: Liverpool Telescope upper limits
  81. EP260626a: EP-WXT detection of a fast X-ray transient
  82. Konus-Wind detection of GRB 260623B / EP260623a
  83. EP260623a: TNG NIR afterglow detection
  84. GRB 260618A: Fermi GBM Observation
  85. MASS-Cube (GRID 2.0) detection of GRB 260616B
  86. EP260623a: FTW optical and NIR observations
  87. GRB 260619A: SVOM/ECLAIRs refined analysis
  88. EP260623a: Liverpool Telescope optical observations
  89. Fermi GBM trigger 804010507/260624677 is not a GRB
  90. GRB 260624A: Fermi GBM Final Real-time Localization
  91. EP260623a:refined analysis of the EP-WXT and EP-FXT observation
  92. EP260623a: WINTER J-band observations
  93. GRB 260617A: Glowbug gamma-ray detection of a short burst
  94. IceCube-260622A: Upper limits from a search for additional neutrino events in IceCube
  95. EP260623a: Optical follow-up observations with Kinder
  96. GRB 260623A: Fermi GBM Final Real-time Localization
  97. EP260623a: SVOM/VT optical observations
  98. EP260623a: TRT optical observations
  99. EP260623a: REM optical/NIR afterglow detection
  100. EP 260623a: COLIBRÍ optical observations

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