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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"

2268 results found.

  1. GRB 260921A: SVOM/GRM observation
  2. GRB 260922A: COLIBRÍ Confirmation of the Optical Counterpart
  3. GRB 260924A: Fermi GRB Observation
  4. GRB 260924A: Fermi-LAT detection of a bright burst
  5. GRB 260924A: AstroSat CZTI detection
  6. GRB 260920A: SVOM/GRM observation
  7. GRB 260924A: NOT optical counterpart confirmation
  8. GRB 260922A: CALET Gamma-Ray Burst Monitor detection
  9. The EP-WXT trigger 01709319842 is likely a flaring star
  10. GRB 260924A: Fermi GBM Final Real-time Localization
  11. Fermi GRB 260923A: Global MASTER-Net observations report
  12. GRB 260923A: Fermi GBM Final Real-time Localization
  13. EP260806a: e-MERLIN detection at 5 GHz
  14. GRB 260922A: Ondrejov D50 optical limit
  15. Fermi-LAT Gamma-ray Observations of IceCube-260919A
  16. Fermi-LAT Gamma-ray Observations of IceCube-260916A
  17. ATCA observations of GRB 260909A
  18. EP260920a: VLT/HAWK-I near-infrared counterpart confirmation
  19. GRB 260922A: J-band upper limit with WINTER
  20. GRB 260922A: COLIBRÍ optical upper limits
  21. Fermi-LAT Gamma-ray Observations of IceCube-260805A
  22. GRB 260920A: Glowbug gamma-ray detection
  23. GRB 260918A: SVOM/ECLAIRs refined analysis
  24. GRB 260922A: SVOM/C-GFT optical upper limit
  25. GRB 260917C: AstroSat CZTI detection
  26. GRB 260920B/EP260920b: GECAM-B detection of a burst
  27. GRB 260921A: AstroSat CZTI detection
  28. GRB 260921B: Fermi GBM Final Localization
  29. GRB 260921A: Fermi GBM Observation
  30. EP260920b: 2.2m CAHA optical afterglow detection and 10.4m GTC redshift confirmation
  31. EP Alert 260921.58: Global MASTER-Net observations report
  32. GRB 260917B:: SVOM/ECLAIRs refined analysis
  33. The EP-WXT trigger 01709319528 is likely a flaring star
  34. EP260920a: VLT/HAWK-I near-infrared candidate
  35. Swift GRB 260921A: Global MASTER-Net observations report
  36. EP260920b: VLT/X-shooter spectroscopic redshift z = 3.582
  37. GRB 260921A: Fermi GBM Final Real-time Localization
  38. EP260920b: LCO observations
  39. GRB 260920A: AstroSat CZTI detection
  40. EP260920b: SVOM/VT optical observation
  41. EP260920b: refined analysis of the EP-WXT and EP-FXT observations
  42. EP260920b: COLIBRÍ optical observations
  43. The EP-WXT trigger 01709318601 is likely a flaring star
  44. EP Alert 260921.01: Global MASTER-Net observations report
  45. EP260920b: Global MASTER-Net observations report
  46. EP260920b: Einstein Probe detection of an X-ray transient
  47. IceCube-260919A: Upper limits from a search for additional neutrino events in IceCube
  48. EP Alert 260920.66: Global MASTER-Net observations report
  49. EP-WXT detected a brightening of HMXB LS V +44 17
  50. EP260920a: NOT early time optical upper limits
  51. EP260920a: NOT optical upper limits
  52. GRB 260920A: Fermi GBM Final Real-time Localization
  53. EP260920a: SVOM/VT optical upper limits
  54. EP260917a: Global MASTER-Net observations report
  55. EP260920a: refined analysis of the EP-WXT and autonomous EP-FXT observations
  56. EP260920a: COLIBRÍ optical upper limits
  57. EP260917b: EP-FXT non-detection and upper limit
  58. IceCube Alert 260919A: Global MASTER-Net observations report
  59. EP260920a: Einstein Probe detection of an X-ray transient
  60. EP Alert 260919.40: Global MASTER-Net observations report
  61. EP260917a: refined analysis of the EP-FXT observations
  62. The EP-WXT trigger 01709318491 is likely a flaring star
  63. EP260806a: Yamaguchi Interferometer radio detections
  64. EP260917a: SVOM/VT optical upper limits
  65. GRB 260918A: SVOM/C-GFT optical upper limits
  66. EP Alert 260918.62: Global MASTER-Net observations report
  67. Fermi GBM Sub-Threshold Detection of GRB 260918A
  68. EP Alert 260918.24: Global MASTER-Net observations report
  69. SVOM GRB260918.16: Global MASTER-Net observations report
  70. The EP-WXT trigger 01709318279 is likely a flaring star
  71. GRB 260918A: SVOM/VT optical upper limits
  72. GRB 260916B: Glowbug gamma-ray detection of a short burst
  73. GRB 260918A: EP-FXT follow-up observation
  74. GRB 260917B: Mondy optical upper limit
  75. EP260917b: EP-WXT detection of an X-ray transient
  76. EP260917A: J-band upper limit with WINTER
  77. EP Alert 260917.32: Global MASTER-Net observations report
  78. GRB 260917B: EP-FXT follow-up observation
  79. EP260917a: COLIBRÍ optical upper limits
  80. GRB 260918A: LCO optical upper limits
  81. EP260917a: Einstein Probe detection of an X-ray transient
  82. GRB 260918A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  83. GRB 260918A: SVOM detection of a burst
  84. GRB 260917C: Fermi GBM Final Real-time Localization
  85. GRB 260916B: Fermi GBM Detection
  86. IceCube-260916A: Upper limits from a search for additional neutrino events in IceCube
  87. GRB 260916B: Fermi GBM Final Localization
  88. GRB 260917A: Glowbug gamma-ray detection
  89. GRB 260915A: SVOM/ECLAIRs refined analysis
  90. GRB 260917B: WINTER J-band observations
  91. GRB 260917B: SVOM/VT optical observations
  92. SVOM GRB260917.16: Global MASTER-Net observations report
  93. GRB 260917B: LCO optical observation
  94. GRB 260917B: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  95. GRB 260917B: SVOM detection of a faint burst
  96. GRB 260917A: BALROG localization (Fermi Trigger 811304653 / GRB 260917100)
  97. GRB 260917A: Fermi GBM Final Real-time Localization
  98. Fermi trigger No 811304653: Global MASTER-Net observations report
  99. The EP-WXT trigger 01709317235 is likely a flaring star
  100. GRB 260915A: J-band upper limit with WINTER

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