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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"

19216 results found.

  1. GRB 260708A: Glowbug gamma-ray detection
  2. GRB 260704A: SVOM/ECLAIRs refined analysis
  3. GRB 260706A : GRANDMA Upper limits
  4. GRB 260708A: GECAM-B observation of a burst
  5. IceCube-260708A: One candidate from the Zwicky Transient Facility
  6. GRB 260708A: Fermi-GBM observation
  7. Fermi LAT GRB 260708A: MASTER OT J150237.02-435307.7 optical counterpart detection
  8. IceCube Alert 260709A: Global MASTER-Net observations report
  9. GRB 260709A: Fermi GBM Final Real-time Localization
  10. LAT GRB260708.42: Global MASTER-Net observations report
  11. GRB260708B: MAXI/GSC detection
  12. GRB 260708A: Fermi-LAT detection
  13. GRB 260705B: SVOM/GRM observation
  14. GRB 260708A: Fermi-GBM detection
  15. GRB 260706A: Further EP-FXT follow-up observation
  16. GRB 260706A: SVOM/VT optical upper limits
  17. EP260707a (by EP-FXT): NOT optical upper limit
  18. EP260707a: LCOGT Optical Upper Limit
  19. Fermi GBM trigger 805087514/260707142 (GRB 260707A) is not a GRB
  20. EP260707a: Einstein Probe detection of an X-ray transient
  21. Nova AT2026oyp (ASASSN-26dt): Pre-outburst Swift UVOT observation
  22. GRB 260705A: Candidate Optical Counterpart from SOAR and Gemini-South and Possible Association with GRB 260705B
  23. GRB 260705C: Glowbug gamma-ray detection of a short burst
  24. GRB 260706A: SVOM/ECLAIRs refined analysis
  25. GRB 260704A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
  26. GRB 260706A: SVOM/GRM observation
  27. GRB 260706A: REM optical/NIR observations
  28. IceCube-260704A: No candidates from the Zwicky Transient Facility
  29. GRB 260706A: LCO optical upper limit
  30. GRB 260706A: EP-FXT follow-up observation
  31. GRB 260707A: Fermi GBM Final Real-time Localization
  32. The EP-WXT trigger 01709274151 is likely a flaring star
  33. The EP-WXT trigger 01709274141 is likely a flaring star
  34. GRB 260706A: Fermi GBM Observation
  35. IceCube-260704A: Upper limits from a search for additional neutrino events in IceCube
  36. GRB 260706A: SVOM detection of a burst
  37. GRB 260706A: Fermi GBM Final Real-time Localization
  38. The EP-WXT trigger 01709274014 is likely a flaring star
  39. IceCube260704A: OHP/T193 optical observations
  40. GRB 260705A: LCO optical upper limits
  41. GRB 260704A: NOT optical upper limits
  42. GRB 260705C: Fermi GBM Final Localization
  43. GRB 260705B: Fermi GBM Final Real-time Localization
  44. Fermi GBM Sub-Threshold Detection of GRB 260705A
  45. GRB 260705A: SVOM detection of a burst
  46. GRB 260704A: EP-FXT follow-up observation
  47. GRB 260629A: SVOM/GRM observation of a short burst
  48. GRB 260629A: GECAM-A observation of a short burst
  49. GRB 260629A: AstroSat CZTI detection
  50. EP260703a: EP-FXT follow-up observation
  51. GRB 260704A: SVOM detection of a possible GRB
  52. GRB 260703B: Fermi GBM Final Localization
  53. EP260703a: EP-WXT detection of a fast X-ray transient
  54. EP260628b: EP-WXT detection of an X-ray transient and EP-FXT follow-up observation
  55. Fermi trigger No 804738310: Global MASTER-Net observations report
  56. Fermi GRB 260703A: Global MASTER-Net observations report
  57. GRB 260703A: Fermi GBM Final Localization
  58. GRB 260610B: VLA detection
  59. GRB 260623A: Glowbug gamma-ray detection
  60. GRB 260610B / AT2026owq: SAO RAS, CrAO and INASAN further optical observations and light curve
  61. Fermi trigger No 804552016: Global MASTER-Net observations report
  62. GRB 260701A: Fermi GBM Final Real-time Localization
  63. Fermi GBM trigger 804552016/260630945 is not a GRB
  64. Fermi-LAT Gamma-ray Observations of IceCube-260622A
  65. EP260628a: EP-FXT follow-up observation
  66. GRB 260629A: Fermi GBM Final Real-time Localization
  67. Fermi GRB 260628A: Global MASTER-Net observations report
  68. EP260628a: EP-WXT detection of a fast X-ray transient
  69. GRB 260628A: Fermi GBM Final Real-time Localization
  70. The EP-WXT trigger 01709272671 is likely a flaring star
  71. EP260626a: further Liverpool Telescope optical upper limits
  72. EP260626a: COLIBRÍ optical upper limit
  73. EP260626a: Liverpool Telescope upper limits
  74. EP260626a: EP-WXT detection of a fast X-ray transient
  75. Konus-Wind detection of GRB 260623B / EP260623a
  76. EP260623a: TNG NIR afterglow detection
  77. GRB 260618A: Fermi GBM Observation
  78. MASS-Cube (GRID 2.0) detection of GRB 260616B
  79. EP260623a: FTW optical and NIR observations
  80. GRB 260619A: SVOM/ECLAIRs refined analysis
  81. EP260623a: Liverpool Telescope optical observations
  82. Fermi GBM trigger 804010507/260624677 is not a GRB
  83. GRB 260624A: Fermi GBM Final Real-time Localization
  84. EP260623a:refined analysis of the EP-WXT and EP-FXT observation
  85. EP260623a: WINTER J-band observations
  86. GRB 260617A: Glowbug gamma-ray detection of a short burst
  87. IceCube-260622A: Upper limits from a search for additional neutrino events in IceCube
  88. EP260623a: Optical follow-up observations with Kinder
  89. GRB 260623A: Fermi GBM Final Real-time Localization
  90. EP260623a: SVOM/VT optical observations
  91. EP260623a: TRT optical observations
  92. EP260623a: REM optical/NIR afterglow detection
  93. EP 260623a: COLIBRÍ optical observations
  94. GRB 260616B/EP260616a: Insight-HXMT/HE detection
  95. EP260623a: OSIRIS+/GTC redshift z = 0.703
  96. EP260623a: Einstein Probe detection of an X-ray transient
  97. GRB 260614B: EP-FXT follow-up observation
  98. GRB 260618C: SVOM/ECLAIRs detection of a possible burst through on-ground search
  99. EP260618a: Liverpool Telescope optical observations
  100. GRB 260618B: LCO optical observations

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