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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"

19197 results found.

  1. Swift trigger 280447 is probably a Galactic transient
  2. GRB 070518: MARGE Observations
  3. GRB 070521: pseudo-z ~ 2.28 from prompt emission spectrum
  4. Konus-Wind observation of GRB 070521
  5. GRB 070521: Swift/UVOT Upper Limits
  6. GRB 070521: Swift-XRT refined analysis
  7. GROND upper limits of GRB 070521
  8. GRB 070521 Milagro GeV/TeV Observations
  9. GRB 070520B: Swift/UVOT Upper Limits
  10. GRB 070521, Swift-BAT refined analysis
  11. GRB 070520A: Swift UVOT Upper Limits
  12. GRB 070520B: Swift-XRT refined analysis
  13. GRB 070521: TAROT La Silla observatory optical observations
  14. GRB070521 - SDSS Pre-Burst Observations
  15. GRB 070521: Swift detection of a burst
  16. GRB 070520B, Swift-BAT refined analysis
  17. GRB 070520A, Swift-BAT refined analysis
  18. GRB 070520A: Swift-XRT refined analysis
  19. GRB 070520B: Swift detection of a burst
  20. GRB 070520: Swift detection of a burst
  21. VLA observation of GRB 070518
  22. GRB 070518: Swift-XRT refined analysis
  23. GRB070518: UVOT refined analysis
  24. GRB 070518, Swift-BAT refined analysis
  25. GRB 070518: Swift detection of a burst with optical afterglow
  26. GRB070517: Swift-XRT Refined Analysis
  27. GRB 070517, Swift-BAT refined analysis
  28. GRB 070517: Swift detection of a burst
  29. GRB 070509: objects inside XRT error circle
  30. GRB 070512: IPN localization and Konus spectrum of a bright burst
  31. GRB 070508: pseudo-z from 4 different spectral analyses
  32. GRB 070509: Swift/UVOT Upper Limits
  33. Konus-Wind and Konus-A observation of GRB 070508
  34. Swift-BAT trigger 278987 is not a GRB
  35. GRB 070510: Swift detection of a possible burst
  36. GRB070509: Swift-XRT Refined Analysis
  37. GRB 070509, Swift-BAT refined analysis
  38. GRB 070508: Suzaku/WAM observation of the prompt emission
  39. GRB 070509: REM observations
  40. GRB 070509: Swift detection of a burst
  41. GRB 070509: ROTSE-III Optical Limits
  42. GRB070508: Swift/UVOT Observations
  43. GRB 070508, Swift-BAT refined analysis
  44. GRB 070508: Swift-XRT refined analysis
  45. GRB 070508: TAROT La Silla observatory optical observations
  46. GRB 070508: Swift detection of an intense burst with an optical counterpart
  47. GRB070412: MAGIC telescope GeV observation
  48. Swift-BAT trigger 278809 is not a GRB
  49. GRB 070507: Swift detection of a possible cosmic ray shower event or a possible burst
  50. GRB070506: Swift/UVOT Observations
  51. GRB070506: Swift XRT refined analysis
  52. GRB 070506, Swift-BAT Refined Analysis
  53. GRB 070506: Swift detection of a burst with optical afterglow
  54. GRB 070429A: Swift XRT further analysis
  55. GRB 070309: Swift-XRT afterglow confirmation
  56. VLA observation of GRB 070429B
  57. Swift/UVOT observations of GRB070429B
  58. GRB 070429B, Swift-BAT refined analysis
  59. Swift/UVOT observations of GRB070429A
  60. GRB 070429A: Swift XRT refined analysis
  61. GRB 070429A, Swift-BAT refined analysis
  62. GRB 070429B: Swift XRT refined analysis
  63. GRB 070429B: ROTSE-III Optical Limits
  64. GRB 070429B: Swift detection of a short burst
  65. GRB 070429: ROTSE-III Optical Limits
  66. GRB 070429: Swift detection of a burst
  67. GRB 070427, Swift-BAT Refined Analysis
  68. GRB 070427: Swift detection of a burst
  69. GRB070419B: Suzaku WAM observation of the prompt emission
  70. GRB 070411, deep LBT photometry
  71. GRB 070420: pseudo-z~1.56 from spectral parameters of the prompt
  72. GRB 070420 Swift-BAT Refined Analysis
  73. GRB070419A: Kuiper Optical detection
  74. GRB070419a: Swift UVOT observations
  75. GRB 070419A: MARGE Observations
  76. GRB 070420: optical rebrightening observed at Mt. John
  77. GRB 070420: Swift XRT refined analysis
  78. GRB070420: Swift UVOT continuing observations
  79. GRB 070420: Faulkes Telescope South Observations
  80. GBR 070419A: Swift/XRT refined analysis
  81. GRB 070420: TAROT La Silla observatory optical observations
  82. GRB 070420: NIR and optical afterglow confirmed
  83. GRB 070420: Swift detection of a burst with optical afterglow
  84. GRB 070419A: Early Super-LOTIS Observations
  85. GRB 070419B, Swift-BAT refined analysis
  86. GRB 070419A Swift-BAT Refined Analysis
  87. GRB 070419A: RAPTOR Detection of Early Emission
  88. GRB 070419B: Swift XRT refined analysis
  89. GRB 070419A, Optical observations
  90. GRB070419 - SDSS Pre-Burst Observations
  91. GRB 070419A: Faulkes Telescope North Optical Observations
  92. GRB 070419B optical afterglow candidate
  93. GRB 070419B: optical afterglow candidate
  94. GRB070419A, optical observation
  95. GRB070330: Correction to UVOT position
  96. GRB 070419B: Swift detection of a burst
  97. GRB 070419A: ROTSE-III Optical Limits
  98. GRB 070419: Swift detection of a burst
  99. Swift-BAT Trigger 276045 is a Cosmic Ray Shower event
  100. Trigger 276045: Swift detection of a possible burst

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