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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"

36036 results found.

  1. GRB 090123: GROND detection
  2. GRB 090123: Swift XRT refined analysis
  3. GRB 090123: Swift/UVOT Observations
  4. AXP 1E1547.0-5408: Suzaku WAM detections of the current activity
  5. GRB 090123: Swift-BAT refined analysis
  6. GRB 090123: Swift detection of a burst
  7. AXP 1E1547.0-5408: long bursts with INTEGRAL SPI-ACS
  8. GRB 090118: Swift XRT Observations - Confirmation of an Afterglow
  9. Swift-BAT trigger 340734 is not a GRB
  10. AXP 1E1547.0-5408: INTEGRAL SPI-ACS confirms activity increase
  11. GRB 090117C: Suzaku WAM observation of the prompt emission
  12. Trigger 340734: Swift detection of a possible short burst
  13. GRB 090118: Subaru NIR Observation
  14. GRB 090118: KPNO 4m 2nd Epoch Observations
  15. GRB 090118 (BATSS): GRT Optical Observation
  16. GRB 090118: KPNO 4m Detection of Candidate Afterglow
  17. GRB 090118: Swift-XRT observations
  18. GRB090118 Swift/UVOT upper limits
  19. GRB 090118: GROND Upper Limits
  20. GRB 090118: Possible burst detection from Swift-BAT slew data
  21. GRB 090117B : Fermi GBM detection
  22. GRB 090117: confirmation of the X-ray afterglow
  23. GRB 090117C - Fermi GRB Detection
  24. GRB 090117 - Fermi GBM Observations
  25. GRB 090117: GROND Upper Limits
  26. GRB090117 Swift/UVOT upper limits
  27. GRB090117: Swift-XRT detection of a possible candidate afterglow
  28. GRB 090117 - SuperAGILE Localization of a long GRB
  29. GRB 090112B: Suzaku WAM observation of the prompt emission
  30. GRB 090113: LOAO Detection Limits in R, I, z, Y-band
  31. GRB 090113: Swift UVOT upper limits
  32. GRB 090113: GROND Upper Limits
  33. GRB 090113: Swift-XRT refined analysis
  34. GRB 090113: Observations from NOT
  35. GRB 090113: Enhanced Swift-XRT position
  36. GRB 090113: Swift-BAT refined analysis
  37. GRB 090113: ROTSE-III Optical Limits
  38. GRB 090112B: Fermi GBM Detection
  39. GRB 090113: Swift detection of a burst
  40. GRB 090112: Fermi GBM detection
  41. GRB 090109: Fermi GBM detection
  42. GRB 090108B: Fermi GBM detection
  43. GRB 090111, Swift-BAT refined analysis
  44. GRB 090111: Swift UVOT Upper Limits
  45. GRB 090108: Fermi GBM Detection
  46. GRB 090111: Swift-XRT refined analysis
  47. GRB 090111: Enhanced Swift-XRT position
  48. GRB 090111: Swift detection of a burst
  49. GRB 090107B: Suzaku WAM observation of the prompt emission
  50. GRB090107B: Fermi GBM Detection
  51. GRB 090102: WSRT Radio Observations
  52. GRB 090107B: Swift XRT afterglow confirmation
  53. GRB 090107B: Swift/UVOT Observations
  54. GRB 090107B: Swift-XRT detection of possible afterglow
  55. GRB 090107B optical observations
  56. GRB 090107B: ROTSE-III Optical Limits
  57. GRB 090107B: a long GRB localized by INTEGRAL
  58. Fermi/GBM detection of GRB 081226A
  59. Fermi/GBM detection of GRB 081225
  60. GRB 090107: Swift-BAT refined analysis
  61. GRB 090107: Swift detection of a burst
  62. GRB 081231: Fermi GBM Detection
  63. GRB 090102: optical decay
  64. VLA radio upper limit on GRB 090102
  65. GRB 090102: GRT Optical Observation
  66. Konus-Wind observation of GRB 090102
  67. GRB 081229: Fermi GBM detection
  68. GRB 090102: Hobby-Eberly Telescope Spectroscopy
  69. GRB 090102: P60 Imaging and P200 Spectroscopy
  70. GRB 090102 Observations from IAC80
  71. GRB 090102: GROND observations of the optical afterglow
  72. Swift UVOT observations of GRB 090102
  73. GRB 090102: Swift-BAT refined analysis
  74. GRB 090102: Swift burst of interest
  75. GRB 090102: Swift XRT refined analysis
  76. GRB 090102: NOT redshift
  77. GRB 090102: Enhanced Swift-XRT position
  78. GRB 090102: TAROT Calern observatory optical light curve
  79. GRB 090102: REM observations of a bright afterglow
  80. GRB 090102: Swift detection of a burst with an optical counterpart
  81. GRB 090102: TAROT Calern observatory optical observations
  82. GRB 081230: GROND confirmation of the afterglow
  83. GRB 081230, Swift-BAT refined analysis
  84. GRB081230: Swift-XRT refined analysis
  85. GRB 081230 Swift/UVOT Observations
  86. GRB 081230: Enhanced Swift-XRT position
  87. GRB 081230: Swift/UVOT Detection of an Optical Afterglow
  88. GRB 081230: ROTSE-III Detection of Optical Counterpart
  89. GRB 081230: Swift detection of a burst
  90. GRB 081228: GROND confirmation of the optical/NIR afterglow
  91. GRB 081226B: Fermi GBM observation
  92. GRB 081226C: Fermi GBM detection
  93. GRB 081228, Swift-BAT refined analysis
  94. VLA radio detection of GRB 081221
  95. GRB 081228: Swift/UVOT Upper Limits
  96. GRB 081228: Swift-XRT Team refined analysis
  97. GRB 081228: detection by GROND
  98. GRB 081228: Enhanced Swift-XRT position
  99. GRB 081228: TAROT Calern observatory optical observations
  100. GRB 081228: Swift detection of a burst

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