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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"

17850 results found.

  1. GRB 090518: Swift/UVOT Upper Limits
  2. GRB 090516: Observations from Stardome Observatory
  3. GRB090518: GROND upper limits
  4. GRB 090518: P60 Observations
  5. GRB 090516, RIMOTS optical upper limits
  6. GRB 090518: Enhanced Swift-XRT position
  7. GRB 090518: Swift detection of a burst
  8. GRB 090516: Swift-BAT refined analysis
  9. GRB 090516: GROND OBSERVATIONS
  10. GRB 090516 - Zadko Telescope observations
  11. GRB 090516: NOT optical observations
  12. GRB 090516: Swift/UVOT Observations
  13. GRB 090516: Enhanced Swift-XRT position
  14. GRB 090516: Swift detection of a burst
  15. GRB 090515: VLA observations
  16. GRB 090515: Lick Upper Limits
  17. GRB 090515: ROVOR Upper Limit
  18. GRB 090515: MMT/MMIRS NIR Upper Limit
  19. GRB 090515: Swift/UVOT Observations
  20. GRB 090515: Enhanced Swift-XRT position
  21. GRB 090509 - Zadko Telescope observations
  22. GRB 090515: Gemini-N upper limit
  23. GRB 090515: WIYN NIR Upper Limit
  24. GRB 090515: PAIRITEL Upper Limits
  25. GRB 090515: Swift detection of a short burst
  26. GRB 090510, Radio limits
  27. GRB090510: VLT/FORS2 spectroscopic redshift
  28. GRB 090510: GROND observations
  29. GRB 090509, further Swift-BAT refined analysis
  30. AGILE detection of GRB 090510
  31. GRB 090510: UVOT refined analysis
  32. GRB 090510: Enhanced Swift-XRT position
  33. GRB 090510: NOT afterglow confirmation
  34. GRB 090509, SMARTS optical/IR afterglow observations
  35. GRB 090510: Swift detection of a short hard burst
  36. GRB 090509: GROND further analysis and redshift limit
  37. GRB 090509: REM NIR afterglow
  38. GRB 090509: GROND afterglow candidate
  39. GRB 090423: 250 GHz upper limit for a z=8.2 GRB with MAMBO-2 at the IRAM 30m
  40. GRB 080913: 250 GHz upper limit for a z=6.7 GRB with MAMBO-2 at the IRAM 30m
  41. GRB 090427: GROND observations
  42. GRB 090429A: ROVOR magnitude limit
  43. GRB 090424, SMARTS optical/IR afterglow monitoring
  44. GRB 090429B: Swift/UVOT Upper Limits
  45. GRB 090429A: Swift/UVOT Upper Limits
  46. GRB 090429B: Gemini-N further nIR observations
  47. GRB 090429A: GROND upper limits
  48. GRB 090429A: Enhanced Swift-XRT position
  49. GRB 090418A BVRcIc field calibration
  50. GRB 090429B: RIMOTS optical upper limits
  51. GRB 090429B: Enhanced Swift-XRT position
  52. GRB090429B: Gemini-N infrared IR candidate
  53. GRB 090429B: VLT upper limits
  54. GRB 090429B: GROND Observations
  55. GRB 090429B: Super-LOTIS early observations
  56. GRB 090429B: Swift detection of a burst
  57. GRB 090429: Swift detection of a burst
  58. GRB 090424 : Multiband Optical observation from Nainital
  59. IPN triangulation of very bright GRB 090427
  60. GRB 090423: CARMA mm observations
  61. GRB 090426: GROND Observations of the Optical/NIR Afterglow
  62. GRB 090423: GROND second epoch imaging and refined SED
  63. Detection of bright radio afterglow of GRB 090424 with the VLA
  64. GRB 090426: Enhanced Swift-XRT position
  65. GRB090426: Observation for Optical counterpart from MIRO
  66. GRB 090426, RIMOTS optical upper limits
  67. GRB 090426: Swift detection of a burst with an optical counterpart
  68. GRB 090424: MASTER-Net prompt optical limit
  69. VLA radio observation of high-z GRB 090423
  70. GRB 090424: THO optical observations
  71. GRB 090424: GROND Observations of the Optical/NIR Afterglow
  72. GRB 090423: Y-band field calibration update/correction
  73. GRB 090424 : TAOS optical detection
  74. GRB 090424: Liverpool Telescope observations
  75. GRB 090424: Optical observations from 1.23m CAHA
  76. GRB 090424: MASTER-Net prompt optical observations
  77. GRB 090424: Enhanced Swift-XRT position
  78. GRB 090424: Swift detection of a burst with an optical counterpart
  79. GRB090423: Y-band field calibration
  80. GRB 090423 limiting magnitudes
  81. GRB 090423: Near infrared observation at Okayama Observatory
  82. GRB 090423: Deep z-band upper limit and confirmation of photo-z
  83. GRB 090423: GROND detection and preliminary photo-z
  84. GRB 090423: NOT z-band limit
  85. GRB 090423: Correction to NIR photometry
  86. GRB090418A Rc-band photometry
  87. GRB 090423: NIR photometry and evidence for spectral break
  88. GRB090423, RIMOTS optical upper limits
  89. GRB 090423: Enhanced Swift-XRT position
  90. GRB 090422: Swift/UVOT Upper Limits
  91. GRB 090423: UKIRT K-band observations
  92. GRB 090423: P60 Observations
  93. GRB 090418A: R and I band observation
  94. GRB 090423: Swift detection of a burst
  95. GRB 090422: Enhanced Swift-XRT position
  96. GRB 090418B: RTT150 optical observations
  97. GRB 080410: GAO 150cm telescope Optical Observation
  98. GRB 080408A: GAO 150cm telescope Optical Observation
  99. GRB 090422: Swift detection of a burst
  100. GRB 090418B: GRAS002 observatios

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