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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"

20587 results found.

  1. GRB 090510: Suzaku WAM observation of the prompt emission
  2. GRB 090510, Radio limits
  3. GRB090510: VLT/FORS2 spectroscopic redshift
  4. GRB 090510: GROND observations
  5. GRB 090509, further Swift-BAT refined analysis
  6. Konus-Wind observation of GRB 090510
  7. AGILE detection of GRB 090510
  8. GRB 090510: UVOT refined analysis
  9. GRB 090510: Enhanced Swift-XRT position
  10. GRB 090510: NOT afterglow confirmation
  11. GRB 090510: Fermi GBM detection
  12. Fermi LAT detection of GRB 090510
  13. GRB 090509, SMARTS optical/IR afterglow observations
  14. GRB 090510: Swift detection of a short hard burst
  15. GRB 090509: GROND further analysis and redshift limit
  16. GRB 090509: REM NIR afterglow
  17. GRB 090509: GROND afterglow candidate
  18. GRB 090423: 250 GHz upper limit for a z=8.2 GRB with MAMBO-2 at the IRAM 30m
  19. GRB 080913: 250 GHz upper limit for a z=6.7 GRB with MAMBO-2 at the IRAM 30m
  20. GRB 090427: GROND observations
  21. GRB 090429A: ROVOR magnitude limit
  22. GRB 090428B: Suzaku WAM observation of the prompt emission
  23. GRB 090424, SMARTS optical/IR afterglow monitoring
  24. GRB 090429B: Swift/UVOT Upper Limits
  25. GRB 090429A: Swift/UVOT Upper Limits
  26. GRB 090429B: Gemini-N further nIR observations
  27. GRB 090429A: GROND upper limits
  28. GRB 090429A: Enhanced Swift-XRT position
  29. GRB 090418A BVRcIc field calibration
  30. GRB 090426: GAO 150cm telescope Optical Observation
  31. GRB 090429B: RIMOTS optical upper limits
  32. GRB 090429B: Enhanced Swift-XRT position
  33. GRB090429B: Gemini-N infrared IR candidate
  34. GRB 090429B: VLT upper limits
  35. GRB 090429B: GROND Observations
  36. GRB 090429B: Super-LOTIS early observations
  37. GRB 090429B: Swift detection of a burst
  38. GRB 090429: Swift detection of a burst
  39. GRB 090424 : Multiband Optical observation from Nainital
  40. IPN triangulation of very bright GRB 090427
  41. GRB 090426: R-band limit
  42. GRB 090423: CARMA mm observations
  43. GRB 090424: Suzaku WAM observation of the prompt emission
  44. GRB 090426: GROND Observations of the Optical/NIR Afterglow
  45. GRB 090423: GROND second epoch imaging and refined SED
  46. Detection of bright radio afterglow of GRB 090424 with the VLA
  47. GRB 090426: Enhanced Swift-XRT position
  48. GRB090426: Observation for Optical counterpart from MIRO
  49. GRB 090426, RIMOTS optical upper limits
  50. GRB 090426: Swift detection of a burst with an optical counterpart
  51. GRB 090424: MASTER-Net prompt optical limit
  52. VLA radio observation of high-z GRB 090423
  53. GRB 090424: THO optical observations
  54. GRB 090424: GROND Observations of the Optical/NIR Afterglow
  55. GRB 090423: Y-band field calibration update/correction
  56. GRB 090424 : TAOS optical detection
  57. GRB 090424: Liverpool Telescope observations
  58. GRB 090424: Optical observations from 1.23m CAHA
  59. GRB 090424: MASTER-Net prompt optical observations
  60. GRB 090424: Enhanced Swift-XRT position
  61. GRB 090424: Swift-BAT refined analysis
  62. GRB 090424: Fermi GBM Observation
  63. GRB 090424: Swift detection of a burst with an optical counterpart
  64. GRB090423: Y-band field calibration
  65. GRB 090423 limiting magnitudes
  66. GRB 090423: Near infrared observation at Okayama Observatory
  67. GRB 090423: Deep z-band upper limit and confirmation of photo-z
  68. GRB 090423: GROND detection and preliminary photo-z
  69. GRB 090423: NOT z-band limit
  70. GRB090418A Rc-band photometry
  71. GRB 090423: NIR photometry and evidence for spectral break
  72. GRB090423, RIMOTS optical upper limits
  73. GRB 090423: Enhanced Swift-XRT position
  74. GRB 090422: Swift/UVOT Upper Limits
  75. GRB 090423: UKIRT K-band observations
  76. GRB 090423: P60 Observations
  77. GRB 090418A: R and I band observation
  78. GRB 090423: Swift detection of a burst
  79. GRB 090418A: Konus-Wind and Swift/BAT joint spectral analysis
  80. GRB 090422: Enhanced Swift-XRT position
  81. GRB 090418B: RTT150 optical observations
  82. GRB 080410: GAO 150cm telescope Optical Observation
  83. GRB 080408A: GAO 150cm telescope Optical Observation
  84. GRB 090418B: Suzaku WAM observation of the prompt emission
  85. GRB 090422: Swift detection of a burst
  86. GRB 090418B: GRAS002 observatios
  87. GRB 090417B: Optical observation
  88. GRB 090418B: GROND observations
  89. GRB 090419: Swift/UVOT Observations
  90. GRB 090418B: Faulkes Telescope North observations
  91. GRB 090418A: Swift/UVOT Observations
  92. GRB 090417B: Swift/UVOT Upper Limits
  93. GRB 090419: Swift-XRT refined analysis
  94. Konus-Wind observation of GRB 090418B
  95. GRB 090419: GROND detection of afterglow candidate
  96. GRB 090418: Optical observations with MITSuME Okayama and Ishigaki 1m telescope
  97. VLA radio detection of GRB 090418
  98. VLA radio upper limit on GRB 090417B
  99. GRB 090419: Enhanced Swift-XRT position
  100. GRB 090418A: ROTSE-III Refined Analysis

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