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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"

24587 results found.

  1. GRB 221016A: Fermi GBM observation
  2. GRB 220926B: Detection by GRBAlpha
  3. MAXI GRB221017.24: Global MASTER-Net observations report
  4. GRB 221016A: LCOGT Optical Afterglow Detection
  5. GRB 221016A: Swift detection of a burst
  6. GRB 221016A: Fermi GBM Final Real-time Localization
  7. Swift GRB221016.99: Global MASTER-Net observations report
  8. GRB 221009A: Faulkes Telescope North continued optical afterglow follow-up
  9. Konus-Wind detection of a short burst coincident with a bright radio burst from SGR 1935+2154
  10. Konus-Wind observation of the recent SGR 1935+2154 activity
  11. GRB 221009A: VLT spectroscopic detection of the host galaxy
  12. GRB 221009A: Armchair Energetics
  13. GRB 221009A: Fermi LAT data rate effects due to extremely high flux
  14. GRB 221009A: Large Binocular Telescope Observatory optical afterglow detection
  15. MAXI/GSC refined analysis of the bright X-ray afterglow of GRB 221009A/Swift J1913.1+1946
  16. GRB 221009A: continued REM optical/NIR observations and evidence for an achromatic steepening in the afterglow light curve
  17. GRB 221009A: IXPE preliminary upper limits of X-ray polarization
  18. GRB 221009A: OHP optical observations
  19. GRB 221009A: HEBS detection
  20. GRB221009A: Gemini-South Optical Afterglow Detection
  21. GRB 221009A: a 397.7 GeV photon observed by Fermi-LAT at 0.4 day after the GBM trigger
  22. GRB 221014A: Fermi GBM Final Real-time Localization
  23. MAXI GRB 221006A: Redshifts of the possible host galaxies
  24. GRB 221009A: search for neutrinos with KM3NeT
  25. GRB221009A: LCOGT Continued Observations - Optical Upper Limits
  26. Fermi trigger No 687345829: Global MASTER-Net observations report
  27. Fermi trigger No 687344475: Global MASTER-Net observations report
  28. Fermi trigger No 687340841: Global MASTER-Net observations report
  29. Fermi trigger No 687337536: Global MASTER-Net observations report
  30. GRB 221009A: MITSuME Okayama optical observation
  31. Fermi trigger No 687281393: Global MASTER-Net observations report
  32. GRB 221013B: Fermi GBM Final Real-time Localization
  33. Integral GRB221013.04: Global MASTER-Net observations report
  34. GRB 221013A: Fermi GBM Final Real-time Localization
  35. Integral GRB221013.00: Global MASTER-Net observations report
  36. Integral GRB221012.99: Global MASTER-Net observations report
  37. Integral GRB221012.94: Global MASTER-Net observations report
  38. Integral GRB221012.91: Global MASTER-Net observations report
  39. Integral GRB221012.88: Global MASTER-Net observations report
  40. Integral GRB221012.87: Global MASTER-Net observations report
  41. Integral GRB221012.77: Global MASTER-Net observations report
  42. Integral GRB221012.74: Global MASTER-Net observations report
  43. Integral GRB221012.72: Global MASTER-Net observations report
  44. Integral GRB221012.71: Global MASTER-Net observations report
  45. Integral GRB221012.68: Global MASTER-Net observations report
  46. Integral GRB221012.68: Global MASTER-Net observations report
  47. Integral GRB221012.98: Global MASTER-Net observations report
  48. Fermi-GBM Observations of High Bursting Activity from SGR J1935+2154
  49. Integral GRB221012.63: Global MASTER-Net observations report
  50. Integral GRB221012.61: Global MASTER-Net observations report
  51. Integral GRB221012.60: Global MASTER-Net observations report
  52. Integral GRB221012.53: Global MASTER-Net observations report
  53. GRB 221009A/Swift J1913.1+1946: eMERLIN observations
  54. Fermi trigger No 687205006: Global MASTER-Net observations report
  55. INTEGRAL detection of a burst from SGR J1935+2154
  56. GRB 220829A: Detection by GRBAlpha
  57. GRB 220826B: Detection by GRBAlpha
  58. GRB 221009A: NuSTAR Detection
  59. GRB 221009A: NICER follow-up observations
  60. GRB 221009A: LCOGT Optical Afterglow Detection
  61. GRB221009A: INTEGRAL detection of Hard X-ray emission up to 38 hours after trigger
  62. Fermi trigger No 687190301: Global MASTER-Net observations report
  63. GRB 221009A (Swift J1913.1+1946): Swift-BAT refined analysis
  64. GRB 221009A: 10.4m GTC spectroscopic redshift confirmation
  65. GRB 221009A: Upper limits from HAWC 8 hours after trigger
  66. GRB 221011A: Fermi GBM Final Real-time Localization
  67. Swift/XRT discovery of multiple dust-scattering X-ray rings around GRB 221009A
  68. GRB 221009A: BlackGEM optical observations
  69. INTEGRAL detection of a burst from SGR J1935+2154
  70. GRB 221006A: CALET Gamma-Ray Burst Monitor detection
  71. Integral GRB221010.89: Global MASTER-Net observations report
  72. Fermi trigger No 687077239: Global MASTER-Net observations report
  73. GRB 221009A: Continued Swift/XRT observations
  74. GRB 221009A/Swift J1913.1+1946: Lick/Nickel telescope optical observations
  75. Konus-Wind detection of GRB 221009A
  76. GRB 221009A: Lulin SLT-40cm optical observations
  77. Swift J1913.1+1946: New Photometry
  78. GRB 221009A: Upper limits from a neutrino search with IceCube
  79. GRB 221009A (Swift J1913.1+1946): Burke-Gaffney Observatory optical observations
  80. GRB221009A/Swift J1913.1+1946: Solar Orbiter STIX measurements
  81. GRB221009A/Swift J1913.1+1946: INTEGRAL SPI/ACS observations
  82. ​GRB 221009A: Multi-color detection of the optical
  83. GRB 221009A: Fermi-LAT refined analysis
  84. GRB221009A/Swift J1913.1+1946: ATA follow-up observations
  85. GRB 221009A: REM optical and NIR detection of the afterglow
  86. GRB 221009A (Swift J1913.1+1946): AGILE/MCAL detection
  87. GRB 221009A: Nanshan/NEXT photometry and Xinglong-2.16m spectroscopy
  88. GRB 221009A (Swift J1913.1+1946): Mondy optical observations
  89. GRB 221009A: Fermi GBM observation
  90. IPN triangulation of extremely bright GRB 221009A
  91. Fermi trigger No 687014224: Global MASTER-Net observations report
  92. GRB 221009A or Swift J1913.1+1946: Fermi-LAT detection
  93. GRB 221009A: Fermi GBM detection of an extraordinarily bright GRB
  94. Swift GRB221009.59: Global MASTER-Net OT detection
  95. GRB 221008A: Swift-XRT observations
  96. GRB 220915A: Detection by GRBAlpha
  97. GRB 221006A: Swift-XRT observations
  98. GRB 220930A: MITSuME Akeno optical upper limits
  99. Fermi trigger No 686588176: Global MASTER-Net observations report
  100. GRB220927A: Detection by GRBAlpha

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