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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"
  1. GRB 070508: Suzaku/WAM observation of the prompt emission
  2. GRB 070509: REM observations
  3. GRB 070509: Swift detection of a burst
  4. GRB 070509: ROTSE-III Optical Limits
  5. GRB070508: Swift/UVOT Observations
  6. GRB 070508, SMARTS optical afterglow observation
  7. GRB 070508, Swift-BAT refined analysis
  8. GRB 070508: Multicolor optical observations and possible redshift limit
  9. GRB 070508: Swift-XRT refined analysis
  10. GRB 070508: Optical observation limiting magnitude
  11. GRB 070508: Optical afterglow detection
  12. GRB 070508: REM observations
  13. GRB 070508: TAROT La Silla observatory optical observations
  14. GRB 070508: Swift detection of an intense burst with an optical counterpart
  15. GRB070412: MAGIC telescope GeV observation
  16. Swift-BAT trigger 278809 is not a GRB
  17. GRB 070507: Swift detection of a possible cosmic ray shower event or a possible burst
  18. GRB 070506: VLT redshift
  19. GRB070506: Swift/UVOT Observations
  20. GRB070506: Swift XRT refined analysis
  21. GRB 070506, Swift-BAT Refined Analysis
  22. GRB 070506: Swift detection of a burst with optical afterglow
  23. GRB 070412, deep LBT imaging
  24. GRB 070429A: Swift XRT further analysis
  25. GRB070429B: VLT observations
  26. GRB 070429A: optical observations
  27. GRB070429B: position correction
  28. GRB 070309: Swift-XRT afterglow confirmation
  29. GRB070429B: possible host galaxy detection
  30. VLA observation of GRB 070429B
  31. Swift/UVOT observations of GRB070429B
  32. GRB 070429B, Swift-BAT refined analysis
  33. Swift/UVOT observations of GRB070429A
  34. GRB 070429A: Swift XRT refined analysis
  35. GRB 070429A, Swift-BAT refined analysis
  36. GRB 070429A: optical and NIR observations
  37. GRB 070429B: Swift XRT refined analysis
  38. GRB 070429B: ROTSE-III Optical Limits
  39. GRB 070429B: Swift detection of a short burst
  40. GRB 070429: What's the temperature?
  41. GRB 070429: ROTSE-III Optical Limits
  42. GRB 070429: Swift detection of a burst
  43. GRB 070427, Swift-BAT Refined Analysis
  44. LT monitoring of GRB070412
  45. GRB 070427: Swift detection of a burst
  46. GRB 070411, further deep LBT photometry
  47. GRB 070411: Late-time Keck imaging
  48. GRB 070411 : Planned XMM-Newton observation
  49. GRB070419B: Suzaku WAM observation of the prompt emission
  50. GRB 070420, SMARTS optical/IR afterglow observations
  51. GRB 070411, deep LBT photometry
  52. GRB 070420: pseudo-z~1.56 from spectral parameters of the prompt
  53. Konus-Wind observation of GRB 070420
  54. GRB 070411: break in the optical light curve
  55. GRB 070420 Swift-BAT Refined Analysis
  56. GRB070419A: Kuiper Optical detection
  57. GRB070419a: Swift UVOT observations
  58. GRB 070419A: MARGE Observations
  59. GRB 070420: optical rebrightening observed at Mt. John
  60. GRB 070420: Swift XRT refined analysis
  61. GRB070420: Swift UVOT continuing observations
  62. GRB 070411: BART early limit
  63. GRB 070420: Faulkes Telescope South Observations
  64. GBR 070419A: Swift/XRT refined analysis
  65. GRB 070420: TAROT La Silla observatory optical observations
  66. GRB 070420: NIR and optical afterglow confirmed
  67. GRB 070420: Swift detection of a burst with optical afterglow
  68. GRB 070419A: MITSuME Okayama Observations
  69. GRB 070419A: Early Super-LOTIS Observations
  70. GRB 070419B, Swift-BAT refined analysis
  71. GRB 070419A Swift-BAT Refined Analysis
  72. GRB070419B: Confirmation of Optical Transient
  73. GRB 070419A: RAPTOR Detection of Early Emission
  74. GRB 070419B: Swift XRT refined analysis
  75. GRB 070419: Keck/LRIS Absorption Redshift
  76. GRB 070419B: optical afterglow confirmation
  77. GRB 070419A, Optical observations
  78. GRB 070411: Deep VLT detection
  79. GRB070419 - SDSS Pre-Burst Observations
  80. GRB 070419A: SARA observations
  81. GRB 070419A: NAYUTA Optical Observation
  82. GRB 070419A: Faulkes Telescope North Optical Observations
  83. GRB 070419B optical afterglow candidate
  84. GRB 070419A: Optical and IR observations with KANATA
  85. GRB 070419B: optical afterglow candidate
  86. GRB 070419A: Lulin Optical observation
  87. GRB070419A, optical observation
  88. Infrared detection of GRB070419A with UKIRT
  89. GRB 070419A: Kiso Optical observation
  90. GRB070330: Correction to UVOT position
  91. GRB 070419: P60 Confirmation of Optical Afterglow
  92. GRB 070419B: Swift detection of a burst
  93. GRB 070419 optical afterglow candidate
  94. GRB 070419A: ROTSE-III Optical Limits
  95. GRB 070419: Swift detection of a burst
  96. Swift-BAT Trigger 276045 is a Cosmic Ray Shower event
  97. GRB 070418: Optical and IR observations with KANATA
  98. Trigger 276045: Swift detection of a possible burst
  99. GRB 070406: Swift XRT refined analysis
  100. IBAS Alert n.4202: not a real GRB

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