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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: OT confirmed form Xinglong TNT observation
  2. GRB 070518: Swift detection of a burst with optical afterglow
  3. GRB070517: Swift-XRT Refined Analysis
  4. GRB 070517, Swift-BAT refined analysis
  5. GRB 070517: Optical search
  6. GRB 070517: Swift detection of a burst
  7. GRB 070509: objects inside XRT error circle
  8. GRB 070512: pseudo-z ~ 1.39 from prompt emission spectrum
  9. GRB 070512: IPN localization and Konus spectrum of a bright burst
  10. GRB070419A: optical observations
  11. GRB 070419A, Deep LBT photometry
  12. GRB 070508: pseudo-z from 4 different spectral analyses
  13. GRB 070509: Swift/UVOT Upper Limits
  14. Konus-Wind and Konus-A observation of GRB 070508
  15. Swift-BAT trigger 278987 is not a GRB
  16. GRB 070510: Swift detection of a possible burst
  17. GRB070509: Swift-XRT Refined Analysis
  18. RHESSI Spectrum of GRB070508
  19. GRB 070508: OA fading and tentative redshift
  20. GRB 070509, Swift-BAT refined analysis
  21. GRB 070508: Suzaku/WAM observation of the prompt emission
  22. GRB 070509: REM observations
  23. GRB 070509: Swift detection of a burst
  24. GRB 070509: ROTSE-III Optical Limits
  25. GRB070508: Swift/UVOT Observations
  26. GRB 070508, SMARTS optical afterglow observation
  27. GRB 070508, Swift-BAT refined analysis
  28. GRB 070508: Multicolor optical observations and possible redshift limit
  29. GRB 070508: Swift-XRT refined analysis
  30. GRB 070508: Optical observation limiting magnitude
  31. GRB 070508: Optical afterglow detection
  32. GRB 070508: REM observations
  33. GRB 070508: TAROT La Silla observatory optical observations
  34. GRB 070508: Swift detection of an intense burst with an optical counterpart
  35. GRB070412: MAGIC telescope GeV observation
  36. Swift-BAT trigger 278809 is not a GRB
  37. GRB 070507: Swift detection of a possible cosmic ray shower event or a possible burst
  38. GRB 070506: VLT redshift
  39. GRB070506: Swift/UVOT Observations
  40. GRB070506: Swift XRT refined analysis
  41. GRB 070506, Swift-BAT Refined Analysis
  42. GRB 070506: Swift detection of a burst with optical afterglow
  43. GRB 070412, deep LBT imaging
  44. GRB 070429A: Swift XRT further analysis
  45. GRB070429B: VLT observations
  46. GRB 070429A: optical observations
  47. GRB070429B: position correction
  48. GRB 070309: Swift-XRT afterglow confirmation
  49. GRB070429B: possible host galaxy detection
  50. VLA observation of GRB 070429B
  51. Swift/UVOT observations of GRB070429B
  52. GRB 070429B, Swift-BAT refined analysis
  53. Swift/UVOT observations of GRB070429A
  54. GRB 070429A: Swift XRT refined analysis
  55. GRB 070429A, Swift-BAT refined analysis
  56. GRB 070429A: optical and NIR observations
  57. GRB 070429B: Swift XRT refined analysis
  58. GRB 070429B: ROTSE-III Optical Limits
  59. GRB 070429B: Swift detection of a short burst
  60. GRB 070429: What's the temperature?
  61. GRB 070429: ROTSE-III Optical Limits
  62. GRB 070429: Swift detection of a burst
  63. GRB 070427, Swift-BAT Refined Analysis
  64. LT monitoring of GRB070412
  65. GRB 070427: Swift detection of a burst
  66. GRB 070411, further deep LBT photometry
  67. GRB 070411: Late-time Keck imaging
  68. GRB 070411 : Planned XMM-Newton observation
  69. GRB070419B: Suzaku WAM observation of the prompt emission
  70. GRB 070420, SMARTS optical/IR afterglow observations
  71. GRB 070411, deep LBT photometry
  72. GRB 070420: pseudo-z~1.56 from spectral parameters of the prompt
  73. Konus-Wind observation of GRB 070420
  74. GRB 070411: break in the optical light curve
  75. GRB 070420 Swift-BAT Refined Analysis
  76. GRB070419A: Kuiper Optical detection
  77. GRB070419a: Swift UVOT observations
  78. GRB 070419A: MARGE Observations
  79. GRB 070420: optical rebrightening observed at Mt. John
  80. GRB 070420: Swift XRT refined analysis
  81. GRB070420: Swift UVOT continuing observations
  82. GRB 070411: BART early limit
  83. GRB 070420: Faulkes Telescope South Observations
  84. GBR 070419A: Swift/XRT refined analysis
  85. GRB 070420: TAROT La Silla observatory optical observations
  86. GRB 070420: NIR and optical afterglow confirmed
  87. GRB 070420: Swift detection of a burst with optical afterglow
  88. GRB 070419A: MITSuME Okayama Observations
  89. GRB 070419A: Early Super-LOTIS Observations
  90. GRB 070419B, Swift-BAT refined analysis
  91. GRB 070419A Swift-BAT Refined Analysis
  92. GRB070419B: Confirmation of Optical Transient
  93. GRB 070419A: RAPTOR Detection of Early Emission
  94. GRB 070419B: Swift XRT refined analysis
  95. GRB 070419: Keck/LRIS Absorption Redshift
  96. GRB 070419B: optical afterglow confirmation
  97. GRB 070419A, Optical observations
  98. GRB 070411: Deep VLT detection
  99. GRB070419 - SDSS Pre-Burst Observations
  100. GRB 070419A: SARA observations

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