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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"

35447 results found.

  1. GRB 090118: no afterglow candidate
  2. GRB 090123: GROND detection
  3. GRB 090123: Swift XRT refined analysis
  4. GRB 090123: Swift/UVOT Observations
  5. AXP 1E1547.0-5408: Suzaku WAM detections of the current activity
  6. GRB 090123: Swift-BAT refined analysis
  7. GRB 090123: Swift detection of a burst
  8. AXP 1E1547.0-5408: long bursts with INTEGRAL SPI-ACS
  9. GRB 090118: Swift XRT Observations - Confirmation of an Afterglow
  10. Swift-BAT trigger 340734 is not a GRB
  11. AXP 1E1547.0-5408: INTEGRAL SPI-ACS confirms activity increase
  12. GRB 090117C: Suzaku WAM observation of the prompt emission
  13. Trigger 340734: Swift detection of a possible short burst
  14. GRB 090118: Subaru NIR Observation
  15. GRB 090118: KPNO 4m 2nd Epoch Observations
  16. GRB 090118 (BATSS): GRT Optical Observation
  17. GRB 090118: KPNO 4m Detection of Candidate Afterglow
  18. GRB 090118: Swift-XRT observations
  19. GRB090118 Swift/UVOT upper limits
  20. GRB 090118: GROND Upper Limits
  21. GRB 090118: Possible burst detection from Swift-BAT slew data
  22. GRB 090117B : Fermi GBM detection
  23. GRB 090117: confirmation of the X-ray afterglow
  24. GRB 090117C - Fermi GRB Detection
  25. GRB 090117 - Fermi GBM Observations
  26. GRB 090117: GROND Upper Limits
  27. GRB090117 Swift/UVOT upper limits
  28. GRB090117: Swift-XRT detection of a possible candidate afterglow
  29. GRB 090117 - SuperAGILE Localization of a long GRB
  30. GRB 090112B: Suzaku WAM observation of the prompt emission
  31. GRB 090113: LOAO Detection Limits in R, I, z, Y-band
  32. GRB 090113: Swift UVOT upper limits
  33. GRB 090113: GROND Upper Limits
  34. GRB 090113: Swift-XRT refined analysis
  35. GRB 090113: Observations from NOT
  36. GRB 090113: Enhanced Swift-XRT position
  37. GRB 090113: Swift-BAT refined analysis
  38. GRB 090113: ROTSE-III Optical Limits
  39. GRB 090112B: Fermi GBM Detection
  40. GRB 090113: Swift detection of a burst
  41. GRB 090112: Fermi GBM detection
  42. GRB 090109: Fermi GBM detection
  43. GRB 090108B: Fermi GBM detection
  44. GRB 090111, Swift-BAT refined analysis
  45. GRB 090111: Swift UVOT Upper Limits
  46. GRB 090108: Fermi GBM Detection
  47. GRB 090111: Swift-XRT refined analysis
  48. GRB 090111: Enhanced Swift-XRT position
  49. GRB 090111: Swift detection of a burst
  50. GRB 090107B: Suzaku WAM observation of the prompt emission
  51. GRB090107B: Fermi GBM Detection
  52. GRB 090102: WSRT Radio Observations
  53. GRB 090107B: Swift XRT afterglow confirmation
  54. GRB 090107B: Swift/UVOT Observations
  55. GRB 090107B: Swift-XRT detection of possible afterglow
  56. GRB 090107B optical observations
  57. GRB 090107B: ROTSE-III Optical Limits
  58. GRB 090107B: a long GRB localized by INTEGRAL
  59. Fermi/GBM detection of GRB 081226A
  60. Fermi/GBM detection of GRB 081225
  61. GRB 090107: Swift-BAT refined analysis
  62. GRB 090107: Swift detection of a burst
  63. GRB 081231: Fermi GBM Detection
  64. GRB 090102: optical decay
  65. VLA radio upper limit on GRB 090102
  66. GRB 090102: GRT Optical Observation
  67. Konus-Wind observation of GRB 090102
  68. GRB 081229: Fermi GBM detection
  69. GRB 090102: Hobby-Eberly Telescope Spectroscopy
  70. GRB 090102: P60 Imaging and P200 Spectroscopy
  71. GRB 090102 Observations from IAC80
  72. GRB 090102: GROND observations of the optical afterglow
  73. Swift UVOT observations of GRB 090102
  74. GRB 090102: Swift-BAT refined analysis
  75. GRB 090102: Swift burst of interest
  76. GRB 090102: Swift XRT refined analysis
  77. GRB 090102: NOT redshift
  78. GRB 090102: Enhanced Swift-XRT position
  79. GRB 090102: TAROT Calern observatory optical light curve
  80. GRB 090102: REM observations of a bright afterglow
  81. GRB 090102: Swift detection of a burst with an optical counterpart
  82. GRB 090102: TAROT Calern observatory optical observations
  83. GRB 081230: GROND confirmation of the afterglow
  84. GRB 081230, Swift-BAT refined analysis
  85. GRB081230: Swift-XRT refined analysis
  86. GRB 081230 Swift/UVOT Observations
  87. GRB 081230: Enhanced Swift-XRT position
  88. GRB 081230: Swift/UVOT Detection of an Optical Afterglow
  89. GRB 081230: ROTSE-III Detection of Optical Counterpart
  90. GRB 081230: Swift detection of a burst
  91. GRB 081228: GROND confirmation of the optical/NIR afterglow
  92. GRB 081226B: Fermi GBM observation
  93. GRB 081226C: Fermi GBM detection
  94. GRB 081228, Swift-BAT refined analysis
  95. VLA radio detection of GRB 081221
  96. GRB 081228: Swift/UVOT Upper Limits
  97. GRB 081228: Swift-XRT Team refined analysis
  98. GRB 081228: detection by GROND
  99. GRB 081228: Enhanced Swift-XRT position
  100. GRB 081228: TAROT Calern observatory optical observations

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