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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 070518: Swift-XRT refined analysis
  2. GRB 070517: Gemini optical imaging
  3. GRB070518: UVOT refined analysis
  4. GRB070518: OSN observation
  5. GRB 070518, Swift-BAT refined analysis
  6. GRB 070518: OT confirmed form Xinglong TNT observation
  7. GRB 070518: Swift detection of a burst with optical afterglow
  8. GRB070517: Swift-XRT Refined Analysis
  9. GRB 070517, Swift-BAT refined analysis
  10. GRB 070517: Optical search
  11. GRB 070517: Swift detection of a burst
  12. GRB 070509: objects inside XRT error circle
  13. GRB 070512: pseudo-z ~ 1.39 from prompt emission spectrum
  14. GRB 070512: IPN localization and Konus spectrum of a bright burst
  15. GRB070419A: optical observations
  16. GRB 070419A, Deep LBT photometry
  17. GRB 070508: pseudo-z from 4 different spectral analyses
  18. GRB 070509: Swift/UVOT Upper Limits
  19. Konus-Wind and Konus-A observation of GRB 070508
  20. Swift-BAT trigger 278987 is not a GRB
  21. GRB 070510: Swift detection of a possible burst
  22. GRB070509: Swift-XRT Refined Analysis
  23. RHESSI Spectrum of GRB070508
  24. GRB 070508: OA fading and tentative redshift
  25. GRB 070509, Swift-BAT refined analysis
  26. GRB 070508: Suzaku/WAM observation of the prompt emission
  27. GRB 070509: REM observations
  28. GRB 070509: Swift detection of a burst
  29. GRB 070509: ROTSE-III Optical Limits
  30. GRB070508: Swift/UVOT Observations
  31. GRB 070508, SMARTS optical afterglow observation
  32. GRB 070508, Swift-BAT refined analysis
  33. GRB 070508: Multicolor optical observations and possible redshift limit
  34. GRB 070508: Swift-XRT refined analysis
  35. GRB 070508: Optical observation limiting magnitude
  36. GRB 070508: Optical afterglow detection
  37. GRB 070508: REM observations
  38. GRB 070508: TAROT La Silla observatory optical observations
  39. GRB 070508: Swift detection of an intense burst with an optical counterpart
  40. GRB070412: MAGIC telescope GeV observation
  41. Swift-BAT trigger 278809 is not a GRB
  42. GRB 070507: Swift detection of a possible cosmic ray shower event or a possible burst
  43. GRB 070506: VLT redshift
  44. GRB070506: Swift/UVOT Observations
  45. GRB070506: Swift XRT refined analysis
  46. GRB 070506, Swift-BAT Refined Analysis
  47. GRB 070506: Swift detection of a burst with optical afterglow
  48. GRB 070412, deep LBT imaging
  49. GRB 070429A: Swift XRT further analysis
  50. GRB070429B: VLT observations
  51. GRB 070429A: optical observations
  52. GRB070429B: position correction
  53. GRB 070309: Swift-XRT afterglow confirmation
  54. GRB070429B: possible host galaxy detection
  55. VLA observation of GRB 070429B
  56. Swift/UVOT observations of GRB070429B
  57. GRB 070429B, Swift-BAT refined analysis
  58. Swift/UVOT observations of GRB070429A
  59. GRB 070429A: Swift XRT refined analysis
  60. GRB 070429A, Swift-BAT refined analysis
  61. GRB 070429A: optical and NIR observations
  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: What's the temperature?
  66. GRB 070429: ROTSE-III Optical Limits
  67. GRB 070429: Swift detection of a burst
  68. GRB 070427, Swift-BAT Refined Analysis
  69. LT monitoring of GRB070412
  70. GRB 070427: Swift detection of a burst
  71. GRB 070411, further deep LBT photometry
  72. GRB 070411: Late-time Keck imaging
  73. GRB 070411 : Planned XMM-Newton observation
  74. GRB070419B: Suzaku WAM observation of the prompt emission
  75. GRB 070420, SMARTS optical/IR afterglow observations
  76. GRB 070411, deep LBT photometry
  77. GRB 070420: pseudo-z~1.56 from spectral parameters of the prompt
  78. Konus-Wind observation of GRB 070420
  79. GRB 070411: break in the optical light curve
  80. GRB 070420 Swift-BAT Refined Analysis
  81. GRB070419A: Kuiper Optical detection
  82. GRB070419a: Swift UVOT observations
  83. GRB 070419A: MARGE Observations
  84. GRB 070420: optical rebrightening observed at Mt. John
  85. GRB 070420: Swift XRT refined analysis
  86. GRB070420: Swift UVOT continuing observations
  87. GRB 070411: BART early limit
  88. GRB 070420: Faulkes Telescope South Observations
  89. GBR 070419A: Swift/XRT refined analysis
  90. GRB 070420: TAROT La Silla observatory optical observations
  91. GRB 070420: NIR and optical afterglow confirmed
  92. GRB 070420: Swift detection of a burst with optical afterglow
  93. GRB 070419A: MITSuME Okayama Observations
  94. GRB 070419A: Early Super-LOTIS Observations
  95. GRB 070419B, Swift-BAT refined analysis
  96. GRB 070419A Swift-BAT Refined Analysis
  97. GRB070419B: Confirmation of Optical Transient
  98. GRB 070419A: RAPTOR Detection of Early Emission
  99. GRB 070419B: Swift XRT refined analysis
  100. GRB 070419: Keck/LRIS Absorption Redshift

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