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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"

24382 results found.

  1. Konus-Wind and Konus-A observation of GRB 070508
  2. GRB 070510: Swift detection of a possible burst
  3. RHESSI Spectrum of GRB070508
  4. GRB 070509, Swift-BAT refined analysis
  5. GRB 070508: Suzaku/WAM observation of the prompt emission
  6. GRB 070509: ROTSE-III Optical Limits
  7. GRB070508: Swift/UVOT Observations
  8. GRB 070508, SMARTS optical afterglow observation
  9. GRB 070508, Swift-BAT refined analysis
  10. GRB 070508: Multicolor optical observations and possible redshift limit
  11. GRB070412: MAGIC telescope GeV observation
  12. GRB 070506, Swift-BAT Refined Analysis
  13. GRB070429B: VLT observations
  14. GRB 070309: Swift-XRT afterglow confirmation
  15. Swift/UVOT observations of GRB070429B
  16. GRB 070429B, Swift-BAT refined analysis
  17. Swift/UVOT observations of GRB070429A
  18. GRB 070429A, Swift-BAT refined analysis
  19. GRB 070429B: ROTSE-III Optical Limits
  20. GRB 070429: ROTSE-III Optical Limits
  21. GRB 070427, Swift-BAT Refined Analysis
  22. GRB 070411: Late-time Keck imaging
  23. GRB070419B: Suzaku WAM observation of the prompt emission
  24. GRB 070420, SMARTS optical/IR afterglow observations
  25. GRB 070411, deep LBT photometry
  26. GRB 070411: break in the optical light curve
  27. GRB 070420 Swift-BAT Refined Analysis
  28. GRB070419A: Kuiper Optical detection
  29. GRB 070419A: MARGE Observations
  30. GRB 070420: Faulkes Telescope South Observations
  31. GBR 070419A: Swift/XRT refined analysis
  32. GRB 070420: NIR and optical afterglow confirmed
  33. GRB 070419A: MITSuME Okayama Observations
  34. GRB 070419B, Swift-BAT refined analysis
  35. GRB 070419A Swift-BAT Refined Analysis
  36. GRB 070419A: RAPTOR Detection of Early Emission
  37. GRB 070419A: Faulkes Telescope North Optical Observations
  38. GRB070419A, optical observation
  39. GRB 070419: P60 Confirmation of Optical Afterglow
  40. GRB 070419A: ROTSE-III Optical Limits
  41. GRB 070418: Optical and IR observations with KANATA
  42. Trigger 276045: Swift detection of a possible burst
  43. IBAS Alert n.4202: not a real GRB
  44. GRB 070318, SMARTS optical/IR afterglow observations
  45. GRB070412: Swift UVOT observations
  46. IBAS Alert n.4199: Not a GRB
  47. GRB 070412, Swift-BAT refined analysis
  48. GRB 070412 Liverpool Telescope optical limit
  49. GRB 070411: Optical photometry at Crni Vrh
  50. GRB 070411, Swift-BAT refined analysis
  51. GRB 070412: Swift detection of a burst
  52. GRB 070411 : Liverpool Telescope Observations
  53. GRB 070411: ROTSE-III Detection of Optical Counterpart
  54. GRB 070406, Swift-BAT refined analysis
  55. GRB 070406: Correction to the optical candidate in GCN6253
  56. GRB 070406: Gemini South Imaging and XRT analysis
  57. GRB 070406: NOT observations
  58. GRB 070406: The exprosure time of Xinglong TNT optical Upper Limit
  59. GRB 070402: Suzaku WAM observation of the prompt emission
  60. GRB 070328: Suzaku WAM observation of the prompt emission
  61. INTEGRAL ToO Observation of SGR1806-20
  62. UVOT observations of GRB070330
  63. GRB 070330, Swift-BAT refined analysis
  64. GRB 070330, SMARTS optical/IR observations
  65. GRB 070330 - Watcher Observations
  66. GRB 070328: pseudo-z~2.75 from spectral parameters of the prompt
  67. Konus-Wind observation of GRB 070328
  68. long burst from SGR 1806-20 detected on March 26
  69. GRB 070328, Swift-BAT refined analysis
  70. GRB070220: optical observations
  71. GRB070208: optical observations
  72. GRB070318: Swift UVOT indicates unusual optical/UV afterglow
  73. Short-Hard GRB 070209: PROMPT Observations
  74. GRB 070318: absorption-line redshift
  75. GRB070318: Swift UVOT continuing observations
  76. GRB 070318, Swift-BAT refined analysis
  77. IBAS Alert n. 4176: not a GRB
  78. GRB 070311: Tautenburg sees afterglow fading
  79. IBAS Alert n. 4169: not a GRB
  80. GRB 070311: Optical observation.
  81. GRB 070309: variability of the XRT afterglow candidate
  82. GRB 070311: RAPTOR Detection of Optical Emission
  83. GRB 070311: MDM Optical Detection
  84. GRB 070311: MITSuME Okayama Optical Observation
  85. GRB 070311: Swift-XRT refined analysis
  86. GRB 070311: REM candidate afterglow
  87. GRB 070311: a long GRB detected by INTEGRAL
  88. GRB060901: Candidate optical afterglow
  89. GRB 070309: A long GRB detected by INTEGRAL
  90. GRB 070125: X-ray light curve analysis
  91. IBAS Alert 4162: Not a GRB
  92. GRB 070306: NOT observations
  93. GRB 070306, Swift-BAT refined analysis
  94. GRB 070306: XRT Team Refined Analysis
  95. GRB 070306: Optical and IR observations with KANATA
  96. GRB070227: Swift-XRT refined analysis
  97. GRB 070125, deep late-time optical observation
  98. GRB 070223: Optical Observations
  99. GRB 070227, Swift-BAT refined analysis
  100. GRB 920925C: optical afterglow candidate

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