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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"

2271 results found.

  1. GRB 260924A: NuSTAR detection of prompt emission
  2. GRB 260922A: NuSTAR detection of prompt emission
  3. GRB 260921A: NuSTAR detection of prompt emission
  4. GRB 260921A: SVOM/GRM observation
  5. GRB 260922A: COLIBRÍ Confirmation of the Optical Counterpart
  6. GRB 260924A: Fermi GRB Observation
  7. GRB 260924A: Fermi-LAT detection of a bright burst
  8. GRB 260924A: AstroSat CZTI detection
  9. GRB 260920A: SVOM/GRM observation
  10. GRB 260924A: NOT optical counterpart confirmation
  11. GRB 260922A: CALET Gamma-Ray Burst Monitor detection
  12. The EP-WXT trigger 01709319842 is likely a flaring star
  13. GRB 260924A: Fermi GBM Final Real-time Localization
  14. Fermi GRB 260923A: Global MASTER-Net observations report
  15. GRB 260923A: Fermi GBM Final Real-time Localization
  16. EP260806a: e-MERLIN detection at 5 GHz
  17. GRB 260922A: Ondrejov D50 optical limit
  18. Fermi-LAT Gamma-ray Observations of IceCube-260919A
  19. Fermi-LAT Gamma-ray Observations of IceCube-260916A
  20. ATCA observations of GRB 260909A
  21. EP260920a: VLT/HAWK-I near-infrared counterpart confirmation
  22. GRB 260922A: J-band upper limit with WINTER
  23. GRB 260922A: COLIBRÍ optical upper limits
  24. Fermi-LAT Gamma-ray Observations of IceCube-260805A
  25. GRB 260920A: Glowbug gamma-ray detection
  26. GRB 260918A: SVOM/ECLAIRs refined analysis
  27. GRB 260922A: SVOM/C-GFT optical upper limit
  28. GRB 260917C: AstroSat CZTI detection
  29. GRB 260920B/EP260920b: GECAM-B detection of a burst
  30. GRB 260921A: AstroSat CZTI detection
  31. GRB 260921B: Fermi GBM Final Localization
  32. GRB 260921A: Fermi GBM Observation
  33. EP260920b: 2.2m CAHA optical afterglow detection and 10.4m GTC redshift confirmation
  34. EP Alert 260921.58: Global MASTER-Net observations report
  35. GRB 260917B:: SVOM/ECLAIRs refined analysis
  36. The EP-WXT trigger 01709319528 is likely a flaring star
  37. EP260920a: VLT/HAWK-I near-infrared candidate
  38. Swift GRB 260921A: Global MASTER-Net observations report
  39. EP260920b: VLT/X-shooter spectroscopic redshift z = 3.582
  40. GRB 260921A: Fermi GBM Final Real-time Localization
  41. EP260920b: LCO observations
  42. GRB 260920A: AstroSat CZTI detection
  43. EP260920b: SVOM/VT optical observation
  44. EP260920b: refined analysis of the EP-WXT and EP-FXT observations
  45. EP260920b: COLIBRÍ optical observations
  46. The EP-WXT trigger 01709318601 is likely a flaring star
  47. EP Alert 260921.01: Global MASTER-Net observations report
  48. EP260920b: Global MASTER-Net observations report
  49. EP260920b: Einstein Probe detection of an X-ray transient
  50. IceCube-260919A: Upper limits from a search for additional neutrino events in IceCube
  51. EP Alert 260920.66: Global MASTER-Net observations report
  52. EP-WXT detected a brightening of HMXB LS V +44 17
  53. EP260920a: NOT early time optical upper limits
  54. EP260920a: NOT optical upper limits
  55. GRB 260920A: Fermi GBM Final Real-time Localization
  56. EP260920a: SVOM/VT optical upper limits
  57. EP260917a: Global MASTER-Net observations report
  58. EP260920a: refined analysis of the EP-WXT and autonomous EP-FXT observations
  59. EP260920a: COLIBRÍ optical upper limits
  60. EP260917b: EP-FXT non-detection and upper limit
  61. IceCube Alert 260919A: Global MASTER-Net observations report
  62. EP260920a: Einstein Probe detection of an X-ray transient
  63. EP Alert 260919.40: Global MASTER-Net observations report
  64. EP260917a: refined analysis of the EP-FXT observations
  65. The EP-WXT trigger 01709318491 is likely a flaring star
  66. EP260806a: Yamaguchi Interferometer radio detections
  67. EP260917a: SVOM/VT optical upper limits
  68. GRB 260918A: SVOM/C-GFT optical upper limits
  69. EP Alert 260918.62: Global MASTER-Net observations report
  70. Fermi GBM Sub-Threshold Detection of GRB 260918A
  71. EP Alert 260918.24: Global MASTER-Net observations report
  72. SVOM GRB260918.16: Global MASTER-Net observations report
  73. The EP-WXT trigger 01709318279 is likely a flaring star
  74. GRB 260918A: SVOM/VT optical upper limits
  75. GRB 260916B: Glowbug gamma-ray detection of a short burst
  76. GRB 260918A: EP-FXT follow-up observation
  77. GRB 260917B: Mondy optical upper limit
  78. EP260917b: EP-WXT detection of an X-ray transient
  79. EP260917A: J-band upper limit with WINTER
  80. EP Alert 260917.32: Global MASTER-Net observations report
  81. GRB 260917B: EP-FXT follow-up observation
  82. EP260917a: COLIBRÍ optical upper limits
  83. GRB 260918A: LCO optical upper limits
  84. EP260917a: Einstein Probe detection of an X-ray transient
  85. GRB 260918A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  86. GRB 260918A: SVOM detection of a burst
  87. GRB 260917C: Fermi GBM Final Real-time Localization
  88. GRB 260916B: Fermi GBM Detection
  89. IceCube-260916A: Upper limits from a search for additional neutrino events in IceCube
  90. GRB 260916B: Fermi GBM Final Localization
  91. GRB 260917A: Glowbug gamma-ray detection
  92. GRB 260915A: SVOM/ECLAIRs refined analysis
  93. GRB 260917B: WINTER J-band observations
  94. GRB 260917B: SVOM/VT optical observations
  95. SVOM GRB260917.16: Global MASTER-Net observations report
  96. GRB 260917B: LCO optical observation
  97. GRB 260917B: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  98. GRB 260917B: SVOM detection of a faint burst
  99. GRB 260917A: BALROG localization (Fermi Trigger 811304653 / GRB 260917100)
  100. GRB 260917A: Fermi GBM Final Real-time Localization

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