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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

19551 results found.

  1. GRB 090509, SMARTS optical/IR afterglow observations
  2. GRB 090510: Swift detection of a short hard burst
  3. GRB 090408: optical upper limit
  4. GRB 090509: GROND further analysis and redshift limit
  5. GRB 090509: REM NIR afterglow
  6. GRB 090509: GROND afterglow candidate
  7. GRB 090423: optical limit
  8. GRB 090423: 250 GHz upper limit for a z=8.2 GRB with MAMBO-2 at the IRAM 30m
  9. GRB 080913: 250 GHz upper limit for a z=6.7 GRB with MAMBO-2 at the IRAM 30m
  10. GRB 090427: GROND observations
  11. GRB 090429A: ROVOR magnitude limit
  12. GRB 090424, SMARTS optical/IR afterglow monitoring
  13. GRB 090429D: Fermi GBM detection
  14. GRB 090429C: Fermi GBM detection
  15. GRB 090429B: Swift/UVOT Upper Limits
  16. GRB 090429A: Swift/UVOT Upper Limits
  17. GRB 090429B: Gemini-N further nIR observations
  18. GRB 090429A: GROND upper limits
  19. GRB 090427C: Fermi GBM detection
  20. GRB 090427B: Fermi GBM detection
  21. GRB 090426C: Fermi GBM detection
  22. GRB 090426B: Fermi GBM detection/observation
  23. GRB 090429A: Enhanced Swift-XRT position
  24. Konus-Wind observation of very bright GRB 090427
  25. GRB 090428B: Fermi GBM detection
  26. GRB 090428: Fermi GBM detection
  27. GRB 090418A BVRcIc field calibration
  28. GRB 090429B: RIMOTS optical upper limits
  29. GRB 090429B: Enhanced Swift-XRT position
  30. GRB090429B: Gemini-N infrared IR candidate
  31. GRB 090429B: VLT upper limits
  32. GRB 090429B: GROND Observations
  33. GRB 090429B: Super-LOTIS early observations
  34. GRB 090429B: Swift detection of a burst
  35. GRB 090429: Swift detection of a burst
  36. GRB 090423: pseudo burst at z=1 and its relation to GRB 080913
  37. GRB 090424 : Multiband Optical observation from Nainital
  38. IPN triangulation of very bright GRB 090427
  39. GRB 090423: CARMA mm observations
  40. GRB 090423: millimeter detection
  41. GRB 090425: Fermi GBM detection
  42. GRB 090426: GROND Observations of the Optical/NIR Afterglow
  43. GRB 090423: GROND second epoch imaging and refined SED
  44. Detection of bright radio afterglow of GRB 090424 with the VLA
  45. GRB 090426: Enhanced Swift-XRT position
  46. GRB090426: Observation for Optical counterpart from MIRO
  47. GRB 090426, RIMOTS optical upper limits
  48. GRB 090426: Swift detection of a burst with an optical counterpart
  49. GRB 090424: MASTER-Net prompt optical limit
  50. GRB 090423: Fermi GBM observation (correction of isotropic equivalent energy)
  51. GRB 090424: WHT ISIS spectroscopy
  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 090423: Swift/BAT spectral lag results
  57. GRB 090424 : TAOS optical detection
  58. GRB 090424: Liverpool Telescope observations
  59. GRB 090424: Swift-XRT refined analysis
  60. GRB 090424: Optical observations from 1.23m CAHA
  61. GRB 090423: energetic, luminosity and jet break
  62. GRB 090424: MASTER-Net prompt optical observations
  63. GRB 090424: Enhanced Swift-XRT position
  64. GRB 090424: Fermi GBM Observation
  65. GRB 090423: Fermi GBM observation
  66. GRB 090422: Fermi GBM observation
  67. GRB 090423: Ep,i - Eiso correlation
  68. GRB 090424: Swift detection of a burst with an optical counterpart
  69. GRB090423: Y-band field calibration
  70. GRB 090423 limiting magnitudes
  71. GRB 090423: Near infrared observation at Okayama Observatory
  72. GRB 090423: Deep z-band upper limit and confirmation of photo-z
  73. GRB 090423: GROND detection and preliminary photo-z
  74. GRB 090423: NOT z-band limit
  75. GRB090418A Rc-band photometry
  76. GRB 090423: NIR photometry and evidence for spectral break
  77. GRB090423, RIMOTS optical upper limits
  78. GRB 090423: Enhanced Swift-XRT position
  79. GRB 090422: Swift/UVOT Upper Limits
  80. GRB 090423: UKIRT K-band observations
  81. GRB 090423: P60 Observations
  82. GRB 090418A: R and I band observation
  83. GRB 090423: Swift detection of a burst
  84. GRB 090422: Swift-BAT refined analysis
  85. GRB 090422: Enhanced Swift-XRT position
  86. GRB 090418B: RTT150 optical observations
  87. GRB 080410: GAO 150cm telescope Optical Observation
  88. GRB 080408A: GAO 150cm telescope Optical Observation
  89. GRB 090422: Swift detection of a burst
  90. GRB 090418C: Fermi GBM Detection
  91. GRB 090418B: GRAS002 observatios
  92. GRB 090418B: GROND observations
  93. GRB 090419: Swift/UVOT Observations
  94. GRB 090418B: Faulkes Telescope North observations
  95. GRB 090418A: Swift/UVOT Observations
  96. GRB 090417B: Swift/UVOT Upper Limits
  97. Konus-Wind observation of GRB 090418B
  98. GRB 090419: GROND detection of afterglow candidate
  99. GRB 090418: Optical observations with MITSuME Okayama and Ishigaki 1m telescope
  100. VLA radio detection of GRB 090418

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