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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"

20359 results found.

  1. GRB 090519: NOT refined analysis
  2. GRB 090519: VLT spectroscopic redshift
  3. GRB 090519: GROND observation
  4. GRB 090519: Swift/UVOT Upper Limits
  5. GRB 090519: Enhanced Swift-XRT position
  6. GRB 090519: NOT afterglow candidate
  7. GRB 090519: FARO Chante Perdrix Observatory optical observations
  8. GRB 090519: TAROT Calern observatory optical observations
  9. GRB 090519: Swift detection of a burst
  10. GRB 090518: Swift/UVOT Upper Limits
  11. GRB 090516: Observations from Stardome Observatory
  12. GRB090518: GROND upper limits
  13. GRB 090518: P60 Observations
  14. GRB 090516, RIMOTS optical upper limits
  15. GRB 090518: Enhanced Swift-XRT position
  16. GRB 090518: Swift detection of a burst
  17. GRB 090515: Swift/BAT spectral lag results
  18. GRB 090516: GROND OBSERVATIONS
  19. GRB 090516 - Zadko Telescope observations
  20. GRB 090516: NOT optical observations
  21. GRB 090516: Swift/UVOT Observations
  22. GRB 090516: Enhanced Swift-XRT position
  23. GRB 090516: Swift detection of a burst
  24. GRB 090515: VLA observations
  25. GRB 090515: Lick Upper Limits
  26. GRB 090515: ROVOR Upper Limit
  27. GRB 090515: MMT/MMIRS NIR Upper Limit
  28. GRB 090515: Swift/UVOT Observations
  29. GRB 090515: Enhanced Swift-XRT position
  30. GRB 090509 - Zadko Telescope observations
  31. GRB 090515: Gemini-N upper limit
  32. GRB 090515: WIYN NIR Upper Limit
  33. GRB 090515: PAIRITEL Upper Limits
  34. GRB 090515: Swift detection of a short burst
  35. GRB 090510, Radio limits
  36. GRB090510: VLT/FORS2 spectroscopic redshift
  37. GRB 090510: GROND observations
  38. GRB 090509, further Swift-BAT refined analysis
  39. Konus-Wind observation of GRB 090510
  40. AGILE detection of GRB 090510
  41. GRB 090510: UVOT refined analysis
  42. GRB 090510: Swift XRT refined analysis
  43. GRB 090510: Enhanced Swift-XRT position
  44. GRB 090510: NOT afterglow confirmation
  45. GRB 090509: Swift-BAT refined analysis
  46. GRB 090509, SMARTS optical/IR afterglow observations
  47. GRB 090510: Swift detection of a short hard burst
  48. GRB 090509: GROND further analysis and redshift limit
  49. GRB 090509: REM NIR afterglow
  50. GRB 090509: GROND afterglow candidate
  51. GRB 090423: 250 GHz upper limit for a z=8.2 GRB with MAMBO-2 at the IRAM 30m
  52. GRB 080913: 250 GHz upper limit for a z=6.7 GRB with MAMBO-2 at the IRAM 30m
  53. GRB 090427: GROND observations
  54. GRB 090429A: ROVOR magnitude limit
  55. GRB 090424, SMARTS optical/IR afterglow monitoring
  56. GRB 090429B: Swift/UVOT Upper Limits
  57. GRB 090429A: Swift/UVOT Upper Limits
  58. GRB 090429B: Gemini-N further nIR observations
  59. GRB 090429A: GROND upper limits
  60. GRB 090429A: Enhanced Swift-XRT position
  61. Konus-Wind observation of very bright GRB 090427
  62. GRB 090418A BVRcIc field calibration
  63. GRB 090429B: RIMOTS optical upper limits
  64. GRB 090429B: Swift-BAT refined analysis
  65. GRB 090429B: Enhanced Swift-XRT position
  66. GRB090429B: Gemini-N infrared IR candidate
  67. GRB 090429B: VLT upper limits
  68. GRB 090429B: GROND Observations
  69. GRB 090429B: Super-LOTIS early observations
  70. GRB 090429B: Swift detection of a burst
  71. GRB 090429: Swift detection of a burst
  72. GRB 090424 : Multiband Optical observation from Nainital
  73. IPN triangulation of very bright GRB 090427
  74. GRB 090423: CARMA mm observations
  75. GRB 090426: GROND Observations of the Optical/NIR Afterglow
  76. GRB 090423: GROND second epoch imaging and refined SED
  77. Detection of bright radio afterglow of GRB 090424 with the VLA
  78. GRB 090426: Enhanced Swift-XRT position
  79. GRB090426: Observation for Optical counterpart from MIRO
  80. GRB 090426, RIMOTS optical upper limits
  81. GRB 090426: Swift detection of a burst with an optical counterpart
  82. GRB 090424: MASTER-Net prompt optical limit
  83. VLA radio observation of high-z GRB 090423
  84. GRB 090424: THO optical observations
  85. GRB 090424: GROND Observations of the Optical/NIR Afterglow
  86. GRB 090423: Y-band field calibration update/correction
  87. GRB 090424 : TAOS optical detection
  88. GRB 090424: Liverpool Telescope observations
  89. GRB 090424: Optical observations from 1.23m CAHA
  90. GRB 090423: energetic, luminosity and jet break
  91. GRB 090424: MASTER-Net prompt optical observations
  92. GRB 090424: Enhanced Swift-XRT position
  93. GRB 090424: Swift detection of a burst with an optical counterpart
  94. GRB090423: Y-band field calibration
  95. GRB 090423 limiting magnitudes
  96. GRB 090423: Near infrared observation at Okayama Observatory
  97. GRB 090423: Deep z-band upper limit and confirmation of photo-z
  98. GRB 090423: GROND detection and preliminary photo-z
  99. GRB 090423: NOT z-band limit
  100. GRB090418A Rc-band photometry

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