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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').
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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"

23435 results found.

  1. GRB030324, BVRcIc field photometry
  2. GRB030323, BVRcIc field calibration
  3. GRB 030324 optical observations
  4. IPN triangulation of GRB030320B (annulus)
  5. IPN triangulation of GRB030320 (small error box)
  6. Possible GRB 030320 localized by INTEGRAL
  7. IPN triangulation of GRB030317 (annulus)
  8. IPN triangulation of GRB030307 (annulus)
  9. GRB 030227: Optical limit at RIKEN
  10. GRB 030226 Optical observations
  11. IPN triangulation of GRB030306 (single small error box - REVISED)
  12. IPN triangulation of GRB030306 (single small error box)
  13. IPN triangulation of GRB030306 (two small error boxes)
  14. IPN triangulation of GRB030304 (annulus)
  15. GRB 030227: Optical observations
  16. GRB030226, BVRc observations
  17. Chandra detection of the X-ray afterglow of GRB 030226
  18. GRB 030226, further optical/NIR imaging
  19. GRB030227: Kiso optical upper limit
  20. IPN triangulation of GRB030301 (annulus)
  21. IPN triangulation of GRB030228 (annulus)
  22. GRB030227, BVRcIc field photometry
  23. GRB030226, BVRcIc field calibration
  24. GRB 030228, optical observations
  25. GRB 030227: Confirmed Optical Afterglow (S1-A)
  26. GRB 030227: fading of candidate optical afterglow 'S1-A'
  27. GRB030227:Optical observations
  28. GRB 20030226: Upper limits from recent and historical observations
  29. GRB 030227, possible optical counterpart of XMM-Newton source
  30. GRB030227: Kiso optical observations
  31. GRB 030227: Kyoto optical observation
  32. GRB030227: refined INTEGRAL position
  33. GRB030227 localized by INTEGRAL
  34. IPN triangulation of GRB030225 (annulus)
  35. GRB030226: ESI spectroscopy
  36. GRB 030226 simultaneous optical observations
  37. GRB 030226, optical observations
  38. GRB030226: Optical decay index
  39. IPN triangulation of GRB030223 (annulus)
  40. IPN triangulation of GRB030220 (annulus)
  41. IPN triangulation of GRB030218 (annulus)
  42. IPN triangulation of GRB030217 (small error box)
  43. IPN triangulation of GRB030215C (annulus)
  44. IPN triangulation of GRB030217 (annulus)
  45. IPN triangulation of GRB030216 (annulus)
  46. IPN triangulation of GRB030215A and GRB030215B (annuli)
  47. GRB 030131: marginal optical detection
  48. IPN triangulation of GRB030206 (annulus)
  49. IPN triangulation of GRB030208 (annulus)
  50. GRB 030204: Optical Observations
  51. GRB030204 field photometry
  52. GRB020819: Kiso R and I band observations
  53. GRB030131: Candidate Optical Afterglow
  54. IPN triangulation of GRB030204 (small error box)
  55. IPN triangulation of GRB030202 (annulus)
  56. GRB 030131, optical observations
  57. GRB030131: Kiso optical limit for corrected position
  58. GRB 030131: afterglow candidate
  59. GRB 030115, late-time optical observations
  60. GRB030131: Kiso Observations
  61. GRB 020819: Host galaxy at Radio Position
  62. IPN triangulation of GRB030131
  63. GRB 030131 optical observations
  64. GRB 030131 optical observations
  65. A long GRB detected by INTEGRAL
  66. GRB030115: 1.2 mm upper limits with MAMBO @ IRAM 30m
  67. IPN triangulation of GRB030127 (annulus)
  68. GRB030115 submm upper limit
  69. IPN triangulation of GRB030119 (two large error boxes)
  70. GRB 030115, simultaneous observations by BOOTES-1
  71. GRB 030115: IR observations with IRSF/SIRIUS
  72. IPN triangulation of GRB030115C (large error box)
  73. GRB030115, afterglow candidate
  74. GRB 021211: R-band observations at late-time
  75. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  76. IPN triangulation of GRB030115B (small error box)
  77. GRB 030115 : Possible IR counterpart
  78. Distribution of INTEGRAL SPI-ACS triggers for GRB bursts
  79. GRB 030115: APO Optical Observations
  80. GRB 030115, optical observations
  81. IPN triangulation of GRB030109 (annulus)
  82. IPN triangulation of GRB030105 (large error box)
  83. IPN triangulation of GRB030102B (portion of annulus)
  84. IPN triangulation of GRB030102A (large error box)
  85. Coronas-F -Wind triangulation of GRB030102
  86. IPN triangulation of GRB030102 (annulus)
  87. VLT spectroscopy of the probable host of GRB 021211
  88. IPN triangulation of GRB030101 (two large error boxes)
  89. GRB021226
  90. GRB 021211: Probable Host and Underlying Supernova
  91. IPN triangulation of GRB021223 (two large error boxes)
  92. GRB021211, radio observations
  93. GRB 021112: Evidence for Another Dark Optical Afterglow
  94. GRB 021219: OSN optical observations
  95. GRB021219, optical observations
  96. IPN triangulation of GRB021219
  97. GRB021219, optical observation by MASTER
  98. GRB021219: a long GRB localized by INTEGRAL
  99. GRB021211: APO optical observations
  100. IPN detection of continued activity from SGR1806-20

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