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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"

21770 results found.

  1. GRB 090423: 250 GHz upper limit for a z=8.2 GRB with MAMBO-2 at the IRAM 30m
  2. GRB 080913: 250 GHz upper limit for a z=6.7 GRB with MAMBO-2 at the IRAM 30m
  3. GRB 090427: GROND observations
  4. GRB 090429A: ROVOR magnitude limit
  5. GRB 090428B: Suzaku WAM observation of the prompt emission
  6. GRB 090424, SMARTS optical/IR afterglow monitoring
  7. GRB 090429B: Swift/UVOT Upper Limits
  8. GRB 090429A: Swift/UVOT Upper Limits
  9. GRB 090429B: Gemini-N further nIR observations
  10. GRB 090429A: GROND upper limits
  11. GRB 090429A: Enhanced Swift-XRT position
  12. GRB 090418A BVRcIc field calibration
  13. GRB 090426: GAO 150cm telescope Optical Observation
  14. GRB 090429B: RIMOTS optical upper limits
  15. GRB 090429B: Enhanced Swift-XRT position
  16. GRB090429B: Gemini-N infrared IR candidate
  17. GRB 090429B: VLT upper limits
  18. GRB 090429B: GROND Observations
  19. GRB 090429B: Super-LOTIS early observations
  20. GRB 090429B: Swift detection of a burst
  21. GRB 090429: Swift detection of a burst
  22. GRB 090424 : Multiband Optical observation from Nainital
  23. IPN triangulation of very bright GRB 090427
  24. GRB 090426: R-band limit
  25. GRB 090423: CARMA mm observations
  26. GRB 090424: Suzaku WAM observation of the prompt emission
  27. GRB 090426: GROND Observations of the Optical/NIR Afterglow
  28. GRB 090423: GROND second epoch imaging and refined SED
  29. Detection of bright radio afterglow of GRB 090424 with the VLA
  30. GRB 090426: Enhanced Swift-XRT position
  31. GRB090426: Observation for Optical counterpart from MIRO
  32. GRB 090426, RIMOTS optical upper limits
  33. GRB 090426: Swift detection of a burst with an optical counterpart
  34. GRB 090424: MASTER-Net prompt optical limit
  35. VLA radio observation of high-z GRB 090423
  36. GRB 090424: THO optical observations
  37. GRB 090424: GROND Observations of the Optical/NIR Afterglow
  38. GRB 090423: Y-band field calibration update/correction
  39. GRB 090424 : TAOS optical detection
  40. GRB 090424: Liverpool Telescope observations
  41. GRB 090424: Optical observations from 1.23m CAHA
  42. GRB 090424: MASTER-Net prompt optical observations
  43. GRB 090424: Enhanced Swift-XRT position
  44. GRB 090424: Swift-BAT refined analysis
  45. GRB 090424: Fermi GBM Observation
  46. GRB 090424: Swift detection of a burst with an optical counterpart
  47. GRB090423: Y-band field calibration
  48. GRB 090423 limiting magnitudes
  49. GRB 090423: Near infrared observation at Okayama Observatory
  50. GRB 090423: Deep z-band upper limit and confirmation of photo-z
  51. GRB 090423: GROND detection and preliminary photo-z
  52. GRB 090423: NOT z-band limit
  53. GRB090418A Rc-band photometry
  54. GRB 090423: NIR photometry and evidence for spectral break
  55. GRB090423, RIMOTS optical upper limits
  56. GRB 090423: Enhanced Swift-XRT position
  57. GRB 090422: Swift/UVOT Upper Limits
  58. GRB 090423: UKIRT K-band observations
  59. GRB 090423: P60 Observations
  60. GRB 090418A: R and I band observation
  61. GRB 090423: Swift detection of a burst
  62. GRB 090418A: Konus-Wind and Swift/BAT joint spectral analysis
  63. GRB 090422: Enhanced Swift-XRT position
  64. GRB 090418B: RTT150 optical observations
  65. GRB 080410: GAO 150cm telescope Optical Observation
  66. GRB 080408A: GAO 150cm telescope Optical Observation
  67. GRB 090418B: Suzaku WAM observation of the prompt emission
  68. GRB 090422: Swift detection of a burst
  69. GRB 090418B: GRAS002 observatios
  70. GRB 090417B: Optical observation
  71. GRB 090418B: GROND observations
  72. GRB 090419: Swift/UVOT Observations
  73. GRB 090418B: Faulkes Telescope North observations
  74. GRB 090418A: Swift/UVOT Observations
  75. GRB 090417B: Swift/UVOT Upper Limits
  76. GRB 090419: Swift-XRT refined analysis
  77. Konus-Wind observation of GRB 090418B
  78. GRB 090419: GROND detection of afterglow candidate
  79. GRB 090418: Optical observations with MITSuME Okayama and Ishigaki 1m telescope
  80. VLA radio detection of GRB 090418
  81. VLA radio upper limit on GRB 090417B
  82. GRB 090419: Enhanced Swift-XRT position
  83. GRB 090418A: ROTSE-III Refined Analysis
  84. GRB 090419: Swift detection of a burst
  85. VLA observations of short burst GRB 090417A
  86. GRB 090418B: Detection of a bright burst from Swift-BAT slew data
  87. GRB 090417B: Gemini imaging
  88. GRB 090418: Swift-BAT refined analysis
  89. GRB 090418: Enhanced Swift-XRT position
  90. GRB 090418: Swift detection of a burst with optical afterglow
  91. GRB 090411B: Suzaku WAM observation of the prompt emission
  92. GRB 090411A: Suzaku WAM observation of the prompt emission
  93. GRB 090417B: Subaru NIR Observations
  94. GRB 090417B: MITSuME Okayama optical upper limits
  95. GRB 090417B: optical observations
  96. GRB090417B: optical observations
  97. GRB 090417B: Swift detection of a burst
  98. GRB 090410: Suzaku WAM observation of the prompt emission
  99. GRB 090410: GROND upper limits
  100. GRB 090410: MITSuME optical upper limits

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