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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"

37774 results found.

  1. GRB 190427A: CALET Gamma-Ray Burst Monitor detection
  2. LIGO/Virgo S190425z: RATIR non-detection of the Swift/UVOT source
  3. GRB 190427A: Swift/UVOT Upper Limits
  4. Fermi Trigger 578170097 / GRB 190428783 / GRB190428A: BALROG localization
  5. GRB 190427A, Swift-BAT refined analysis
  6. If you have problems wrt GCN ( GRB, LIGO/Virgo, etc) and need to send email to the operator
  7. GRB 190419A: AstroSat CZTI detection
  8. Fermi GRB190427.19 Global MASTER-Net observations report
  9. GRB 190427A: Fermi GBM detection
  10. GRB 190427A: Lick/Nickel telescope optical observations
  11. GRB 190427A: MITSuME Akeno optical upper limits
  12. GRB 190427A: COATLI Optical Observations
  13. GRB 190427A: RATIR Optical and NIR Observations
  14. LIGO/Virgo S190426c: Insight-HXMT/HE observation
  15. GRB 190427A: BOOTES-1 and BOOTES-5/JGT early follow-up observations
  16. LIGO/Virgo S190425z: Fermi-LAT search for a high-energy gamma-ray counterpart
  17. GRB 190427A: NOT optical observations
  18. GRB 190427A: Swift-XRT observations
  19. GRB 190427A: Swift detection of a short burst
  20. LIGO/Virgo S190426c: Swift/BAT Counterpart Search
  21. LIGO/Virgo S190426c: Fermi GBM Observations
  22. LIGO/Virgo S190426c: INTEGRAL prompt observation
  23. LIGO/Virgo S190425z: Insight-HXMT/HE observation
  24. LIGO/Virgo S190425z: Candidates from the Zwicky Transient Facility
  25. LIGO/Virgo S190425z: Fermi GBM Observations
  26. LIGO/Virgo S190425z: Swift/BAT Counterpart Search
  27. LIGO/Virgo S190425z: INTEGRAL IBIS prompt observation
  28. LIGO/Virgo S190425z: further analysis of INTEGRAL data
  29. LIGO/Virgo S190421ar: Fermi-LAT search for a high-energy gamma-ray counterpart
  30. LIGO/Virgo S190425z: INTEGRAL SPI-ACS prompt observation
  31. Fermi GRB190425.09 Global MASTER-Net observations report
  32. GRB 190424A: Swift-BAT refined analysis
  33. GRB 190424A: Swift detection of a burst
  34. GRB 190422A: Fermi GBM detection
  35. GRB 190422A: Swift/UVOT Upper Limits
  36. LIGO/Virgo S190421ar: Swift/BAT Counterpart Search
  37. GRB 190422A: Swift-BAT refined analysis
  38. GRB 190422A: Swift-XRT refined Analysis
  39. LIGO/Virgo S190421ar: INTEGRAL prompt observation
  40. GRB 190422A: Enhanced Swift-XRT position
  41. Fermi GRB190422.96 Global MASTER-Net observations report
  42. Fermi GRB190422.67 Global MASTER-Net observations report
  43. GRB 190422A: Swift detection of a burst
  44. LIGO/Virgo S190421ar: Fermi-GBM Observations
  45. Konus-Wind observation of GRB 190415A
  46. Fermi GRB190420.98 Global MASTER-Net observations report
  47. Fermi GRB190419.41 Global MASTER-Net observations report
  48. Fermi trigger 576241792 / GRB 190406B: MASTER optical observation
  49. Fermi Trigger 577360542 / GRB 190419414 / GRB190419A: BALROG localization
  50. Fermi GRB190418.92 Global MASTER-Net observations report
  51. GRB 190406B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 576241792)
  52. GRB 190326A: Swift XRT and UVOT follow-up observations
  53. IPN Triangulation of GRB 190415A
  54. Fermi GRB190417.46 Global MASTER-Net observations report
  55. GRB 190415A: Insight-HXMT/HE detection
  56. Fermi Trigger 576994194 / GRB 190415173 / : BALROG localization
  57. Fermi GRB190415.17 Global MASTER-Net observations report
  58. GRB 190407B: AstroSat CZTI detection
  59. Corrections: GRB 190404A (not 140404B ) and GRB 190404B (not 140404C)
  60. GRB 190411A: AstroSat CZTI detection
  61. GRB 190411A: Insight-HXMT/HE detection
  62. LIGO/Virgo S190412m: Fermi-LAT search for a high-energy gamma-ray counterpart
  63. LIGO/Virgo S190412m: Swift/BAT data search
  64. LIGO/Virgo S190412m: Fermi-GBM Observations
  65. LIGO/Virgo S190412m: Insight-HXMT/HE observation
  66. INTEGRAL prompt observation of S190412m
  67. IPN triangulation of GRB 190409B (short)
  68. GRB 190409A: ground analysis reveals a likely spurious event
  69. LIGO/Virgo S190408an: MAXI/GSC Observations
  70. GRB 190404C: MITSuME Akeno and Okayama optical upper limits
  71. Konus-Wind observation of GRB 190404B
  72. LIGO/Virgo ST190408an: Fermi-LAT search for a high-energy gamma-ray counterpart
  73. GRB 190409A: Swift detection of a possible burst
  74. LIGO/Virgo S190408an: Insight-HXMT/HE observation
  75. LIGO/Virgo S190408an: Swift/BAT data search
  76. CORRECTED TARGET NAME: GRB 190408A: MAXI/GSC detection
  77. GRB 140408A: MAXI/GSC detection
  78. INTEGRAL observation of S190408an
  79. LIGO/Virgo S190408an: Fermi GBM Observation
  80. GRB 190404C: Swift-XRT afterglow detection
  81. Fermi Gamma-ray Burst Monitor trigger 576420743/190408536 is not a GRB
  82. Fermi TriggNum 576054086 (GRB 1904204.29) / MASTER OT J071404.52+550304.2: CrAO optical observations
  83. Fermi Trigger 576356086 / GRB 190407788 / : BALROG localization
  84. Hard Fermi GRB190404.29/TriggNum576054086: MASTER optical counterpart discovery near PGC020455
  85. Fermi Trigger 576346051 / GRB 190407672 / GRB 190407A: BALROG localization
  86. GRB 190404B: CALET Gamma-Ray Burst Monitor detection
  87. GRB 190404C: Swift-XRT observations
  88. GRB 190331C: AstroSat CZTI detection
  89. Swift GRB 190331B: Further Swift-XRT observations
  90. GRB 190404B: Tiled Swift observations
  91. GRB 140404C: MAXI/GSC detection
  92. GRB 140404B: MAXI/GSC detection
  93. GRB 190330A: MITSuME Akeno and Okayama optical upper limits
  94. Konus-Wind observation of GRB 190329A
  95. GRB 190331B: BOOTES-3/YA optical observations
  96. GRB 190326B: AstroSat CZTI detection
  97. GRB 190331B: Swift observations of a ground-detected burst
  98. Fermi-LAT Gamma-ray Observations of IceCube-190331A
  99. GRB 190401A: Insight-HXMT/HE detection
  100. GRB 190331C: Insight-HXMT/HE detection

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