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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"

20494 results found.

  1. GRB 090509 - Zadko Telescope observations
  2. GRB 090515: Gemini-N upper limit
  3. GRB 090515: WIYN NIR Upper Limit
  4. GRB 090515: Super-LOTIS Upper Limits
  5. GRB 090515: PAIRITEL Upper Limits
  6. GRB 090515: ROTSE-III Optical Limits
  7. GRB 090515: Swift detection of a short burst
  8. GRB 090510: Suzaku WAM observation of the prompt emission
  9. GRB 090510, Radio limits
  10. GRB090510: VLT/FORS2 spectroscopic redshift
  11. GRB 090510: GROND observations
  12. GRB 090509, further Swift-BAT refined analysis
  13. Konus-Wind observation of GRB 090510
  14. AGILE detection of GRB 090510
  15. GRB 090510: UVOT refined analysis
  16. GRB 090510: Enhanced Swift-XRT position
  17. GRB 090510: NOT afterglow confirmation
  18. GRB 090510: Fermi GBM detection
  19. Fermi LAT detection of GRB 090510
  20. GRB 090509, SMARTS optical/IR afterglow observations
  21. GRB 090510: Swift detection of a short hard burst
  22. GRB 090509: GROND further analysis and redshift limit
  23. GRB 090509: REM NIR afterglow
  24. GRB 090509: GROND afterglow candidate
  25. GRB 090423: 250 GHz upper limit for a z=8.2 GRB with MAMBO-2 at the IRAM 30m
  26. GRB 080913: 250 GHz upper limit for a z=6.7 GRB with MAMBO-2 at the IRAM 30m
  27. GRB 090427: GROND observations
  28. GRB 090429A: ROVOR magnitude limit
  29. GRB 090428B: Suzaku WAM observation of the prompt emission
  30. GRB 090424, SMARTS optical/IR afterglow monitoring
  31. GRB 090429B: Swift/UVOT Upper Limits
  32. GRB 090429A: Swift/UVOT Upper Limits
  33. GRB 090429B: Gemini-N further nIR observations
  34. GRB 090429A: GROND upper limits
  35. GRB 090429A: Enhanced Swift-XRT position
  36. GRB 090418A BVRcIc field calibration
  37. GRB 090426: GAO 150cm telescope Optical Observation
  38. GRB 090429B: RIMOTS optical upper limits
  39. GRB 090429B: Enhanced Swift-XRT position
  40. GRB090429B: Gemini-N infrared IR candidate
  41. GRB 090429B: VLT upper limits
  42. GRB 090429B: GROND Observations
  43. GRB 090429B: Super-LOTIS early observations
  44. GRB 090429B: Swift detection of a burst
  45. GRB 090429: Swift detection of a burst
  46. GRB 090424 : Multiband Optical observation from Nainital
  47. IPN triangulation of very bright GRB 090427
  48. GRB 090426: R-band limit
  49. GRB 090423: CARMA mm observations
  50. GRB 090424: Suzaku WAM observation of the prompt emission
  51. GRB 090426: GROND Observations of the Optical/NIR Afterglow
  52. GRB 090423: GROND second epoch imaging and refined SED
  53. Detection of bright radio afterglow of GRB 090424 with the VLA
  54. GRB 090426: Enhanced Swift-XRT position
  55. GRB090426: Observation for Optical counterpart from MIRO
  56. GRB 090426, RIMOTS optical upper limits
  57. GRB 090426: Swift detection of a burst with an optical counterpart
  58. GRB 090424: MASTER-Net prompt optical limit
  59. VLA radio observation of high-z GRB 090423
  60. GRB 090424: THO optical observations
  61. GRB 090424: GROND Observations of the Optical/NIR Afterglow
  62. GRB 090423: Y-band field calibration update/correction
  63. GRB 090424 : TAOS optical detection
  64. GRB 090424: Liverpool Telescope observations
  65. GRB 090424: Optical observations from 1.23m CAHA
  66. GRB 090424: MASTER-Net prompt optical observations
  67. GRB 090424: Enhanced Swift-XRT position
  68. GRB 090424: Swift-BAT refined analysis
  69. GRB 090424: Fermi GBM Observation
  70. GRB 090424: Swift detection of a burst with an optical counterpart
  71. GRB090423: Y-band field calibration
  72. GRB 090423 limiting magnitudes
  73. GRB 090423: Near infrared observation at Okayama Observatory
  74. GRB 090423: Deep z-band upper limit and confirmation of photo-z
  75. GRB 090423: GROND detection and preliminary photo-z
  76. GRB 090423: NOT z-band limit
  77. GRB090418A Rc-band photometry
  78. GRB 090423: NIR photometry and evidence for spectral break
  79. GRB090423, RIMOTS optical upper limits
  80. GRB 090423: Enhanced Swift-XRT position
  81. GRB 090422: Swift/UVOT Upper Limits
  82. GRB 090423: UKIRT K-band observations
  83. GRB 090423: P60 Observations
  84. GRB 090418A: R and I band observation
  85. GRB 090423: Swift detection of a burst
  86. GRB 090418A: Konus-Wind and Swift/BAT joint spectral analysis
  87. GRB 090422: Enhanced Swift-XRT position
  88. GRB 090418B: RTT150 optical observations
  89. GRB 080410: GAO 150cm telescope Optical Observation
  90. GRB 080408A: GAO 150cm telescope Optical Observation
  91. GRB 090418B: Suzaku WAM observation of the prompt emission
  92. GRB 090422: Swift detection of a burst
  93. GRB 090418B: GRAS002 observatios
  94. GRB 090417B: Optical observation
  95. GRB 090418B: GROND observations
  96. GRB 090419: Swift/UVOT Observations
  97. GRB 090418B: Faulkes Telescope North observations
  98. GRB 090418A: Swift/UVOT Observations
  99. GRB 090417B: Swift/UVOT Upper Limits
  100. GRB 090419: Swift-XRT refined analysis

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