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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

512 results found.

  1. GRB 240403A: Fermi GBM Detection
  2. Fermi trigger No 733097506: Global MASTER-Net observations report
  3. GRB 231215A: further radio observations with the VLA
  4. Konus-Wind detection of GRB 240205B (long / very soft)
  5. IPN triangulation of GRB 240119A (short)
  6. Swift GRB240109.17: Global MASTER-Net observations report
  7. Fermi trigger No 724698747: Global MASTER-Net observations report
  8. IPN triangulation of GRB 231205A
  9. Fermi GRB 231103A: Global MASTER-Net observations report
  10. GRB 231104A: Swift-XRT refined Analysis
  11. GRB 230808A: Fermi GBM Detection
  12. LIGO/Virgo/KAGRA S230802aq: Updated Sky localization and EM Bright Classification
  13. Fermi trigger No 712713532: Global MASTER-Net observations report
  14. LIGO/Virgo/KAGRA S230802aq: Coverage and upper limits from MAXI/GSC observations
  15. LIGO/Virgo/KAGRA S230529ay: Updated Sky localization and EM Bright Classification
  16. LIGO/Virgo S230621bq: Global MASTER-Net observations report
  17. LIGO/Virgo S230621ad: Global MASTER-Net observations report
  18. Fermi GBM-230619: AstroSat CZTI non-detection and upper limits for the sub-threshold candidate
  19. LIGO/Virgo S230620al: Global MASTER-Net observations report
  20. LIGO/Virgo S230620g: Global MASTER-Net observations report
  21. LIGO/Virgo S230604z: Global MASTER-Net observations report
  22. LIGO/Virgo/KAGRA S230529ay: Identification of a GW compact binary merger candidate
  23. IceCube Alert 230524.47: Global MASTER-Net observations report
  24. Fermi trigger No 705503315: Global MASTER-Net observations report
  25. GRB 230307A: JWST second-epoch observations
  26. Trigger 1160641: Swift detection of 4U 1630-472 (a.k.a. SWIFT J1633.8-4724A)
  27. TESS Detection of the Optical Afterglow of GRB230307A
  28. Konus-Wind detection of GRB 230307A
  29. GRB 221120A: Fermi GBM observation
  30. GRB 221120A: GIT upper limits on optical afterglow
  31. GRB 221025A: AstroSat CZTI detection
  32. Fermi trigger No 687345829: Global MASTER-Net observations report
  33. Fermi trigger No 687344475: Global MASTER-Net observations report
  34. Integral GRB221013.04: Global MASTER-Net observations report
  35. Fermi trigger No 687014224: Global MASTER-Net observations report
  36. Fermi trigger No 681998863: Global MASTER-Net observations report
  37. Fermi GRB 220610A: Global MASTER-Net observations report
  38. Konus-Wind detection of GRB 220601A
  39. GRB 220521A: classification and detection by SPI-ACS/INTEGRAL
  40. GRB 220430A: AstroSat CZTI detection
  41. GRB 220427A: Swift-BAT refined analysis
  42. GRB 220421B: Detection by VZLUSAT-2
  43. IPN triangulation of GRB 220403C
  44. Fermi GRB 220411A: Global MASTER-Net observations report
  45. GRB 220319A: MASTER Global Robotic Net optical observations
  46. Fermi trigger No 663899819: Global MASTER-Net observations report
  47. Fermi trigger No 663710289: Global MASTER-Net observations report
  48. Swift GRB211227.98: Global MASTER-Net observations report
  49. Fermi GRB 211216B: Global MASTER-Net observations report
  50. Fermi GRB 211211B: Global MASTER-Net observations report
  51. GRB 211207A: Swift-BAT refined analysis
  52. Fermi GRB 211204A: Global MASTER-Net observations report
  53. GRB 211129A: Swift-XRT refined Analysis
  54. GRB 211120548: Fermi GBM observation
  55. GRB 211120A: AGILE detection
  56. Swift GRB211010.45: Global MASTER-Net observations report
  57. Fermi trigger No 655401471: Global MASTER-Net observations report
  58. Fermi trigger No 652911693: Global MASTER-Net observations report
  59. Fermi trigger No 652906639: Global MASTER-Net observations report
  60. Swift GRB 210818A: Global MASTER-Net observations report
  61. Fermi trigger No 649627691: Global MASTER-Net observations report
  62. GRB 210731A: Swift-XRT refined Analysis
  63. GRB 210731A: Swift/UVOT Detection of an optical afterglow
  64. Trigger 1062273: Swift detection of 4U 1700-377
  65. Fermi trigger No 649390368: Global MASTER-Net observations report
  66. GRB 210727A: AGILE/MCAL detection
  67. GRB 210722A: Fermi GBM observation
  68. GRB 210722A: Swift/UVOT Detection
  69. Fermi trigger No 647653174: Global MASTER-Net observations report
  70. Fermi trigger No 647641569: Global MASTER-Net observations report
  71. Swift GRB210708.10: Global MASTER-Net observations report
  72. Integral GRB210707.02: Global MASTER-Net observations report
  73. Swift-BAT Trigger 1055000/GRB210612.54: MASTER optical source observation
  74. Swift-BAT Trigger 1055000: Swift detection of an outburst from 4U 1543-47
  75. GRB 210606A: Fermi GBM detection
  76. Swift J1555.2-5402: Swift XRT refined analysis of the new SGR
  77. GRB 210520A: Swift-XRT observations
  78. GRB 210521A: MAXI/GSC detection
  79. Swift trigger 1047857 is 4U 1700-377
  80. Konus-Wind detection of GRB 210424B
  81. IceCube Alert 210416.09: Global MASTER-Net observations report
  82. GECAM detection of a burst possibly from the X-ray burster 4U 0614+09 or GRB 210124A
  83. GRB 210116A: AstroSat CZTI detection
  84. GRB 210119A: Insight-HXMT/HE detection
  85. Konus-Wind observation of GRB 201218A
  86. Swift GRB201209.24: Global MASTER-Net observations report
  87. Fermi trigger No 626247072: Global MASTER-Net observations report
  88. Baksan Neutrino Observatory Alert 201027.41: Global MASTER-Net observations report
  89. GRB 201021C: Swift-XRT refined Analysis
  90. Swift GRB201021.85: Global MASTER-Net observations report
  91. Fermi GRB 200929A: Global MASTER-Net observations report
  92. GRB 200919A: Swift-BAT refined analysis
  93. GRB 200914A: Fermi GBM observation
  94. Fermi GRB 200904A: Global MASTER-Net observations report
  95. AGILE detection of a burst (AGILE trigger no. 526185273)
  96. GRB 200829A: AGILE/MCAL detection
  97. Fermi-GBM Sub-Threshold candidate for GRB 200729A
  98. LIGO/Virgo MS200614bz: Test Identification of a binary neutron star candidate
  99. Fermi GRB 200607B: Global MASTER-Net observations report
  100. GRB 200528A: Swift-BAT refined analysis

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