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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"

3114 results found.

  1. IPN triangulation of GRB030715 (two large error boxes)
  2. GRB030329 -- RATAN-600 data in April-May
  3. GRB 030329: Optical limit (contemporaneous imaging)
  4. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  5. IPN triangulation of GRB030425 (single error box)
  6. GRB 030329, the review of the sky area in plate archive (1950-1998)
  7. IPN triangulation of GRB030422 (two large error boxes)
  8. GRB030329: 444 AAVSO Measurements
  9. GRB 030329, nearby galaxies
  10. Further AAVSO V,B,R observations of GRB030329
  11. GRB 030329: Correction to GCN 2056
  12. GRB 030329: optical observations
  13. GRB030323, ROTSE-III detection of possible optical counterpart
  14. GRB030323, possible optical counterpart
  15. IPN triangulation of GRB030320 (small error box)
  16. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  17. GRB 030217: Optical Observations at 4, 5, and 6 Days
  18. GRB030131: Kiso Observations
  19. IPN triangulation of GRB030101 (two large error boxes)
  20. GRB021004, late time optical observations
  21. Improved IPN error box for GRB021125
  22. IPN BURST POSITION
  23. IPN triangulation of GRB021125 (INTEGRAL BURST)
  24. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  25. GRB021104: optical observations
  26. GRB021104: possible optical afterglow
  27. IPN triangulation of GRB021027 (single large error box)
  28. GRB021004, late-time optical observations
  29. GRB 021004: optical observations
  30. IPN triangulation of GRB021020
  31. GRB021016(=H2397): A Long GRB Localized by HETE
  32. IPN triangulation of GRB021016 (small error box)
  33. IPN triangulation of GRB021008 (two small error boxes)
  34. GRB021004: optical observations and predicted break time
  35. GRB021004: BVRc photometry
  36. GRB 021004: optical counterpart
  37. GRB 021004, SPM optical observations
  38. IPN triangulation of GRB020923 (two error boxes)
  39. Confirmation of IPN error box for GRB020910
  40. IPN triangulation of GRB020910
  41. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  42. INTEGRAL GRBs added to GCN
  43. IPN error box for GRB020813
  44. GRB020813: Candidate Optical Afterglow
  45. Correction to IPN error box for GRB020706
  46. GRB 020625, optical observations
  47. GRB 020531: optical photometry of Chandra sources
  48. GRB020604, optical observations
  49. GRB020531: Observations with the Chandra X-ray Observatory
  50. Correction to IPN triangulation of GRB020603 (possible short/hard burst)
  51. GRB 020124: Optical observations
  52. GRB 020331 Kyoto observation on March 31
  53. GRB020317: optical observations
  54. GRB020321 optical observations
  55. IPN Upper Limits to a GRB Associated With SN2002ap
  56. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  57. GRB020127: Chandra Observations and Prospective Counterparts
  58. GRB 011211, Optical Observations
  59. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  60. GRB011130 (XRF011130) Chandra Observations
  61. GRB011121: fainter still
  62. BEPPOSAX GRB011121
  63. XRF011030: Chandra Observations
  64. Millimeter observation of SGR 1900+14
  65. IPN Triangulation of GRB010412
  66. GRB010214, candidate optical afterglow
  67. GRB010214 Optical Observation
  68. IPN TRIANGULATION OF GRB010109
  69. IPN TRIANGULATION OF GRB010109
  70. XMM-Newton observation of GRB001025
  71. IPN TRIANGULATION OF GRB001020
  72. IPN TRIANGULATION OF GRB001018
  73. GRB000926 - Amateur Optical Observations
  74. GRB 000926 Chandra Observation
  75. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  76. J and K band observations of GRB 000926
  77. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  78. GRB 000926, Optical Observation
  79. GRB 000926: Optical candidate
  80. Optical candidate for GRB000926
  81. GRB000911: Sub-millimeter observations
  82. IPN localization of GRB000812
  83. IPN localization of GRB000811
  84. GRB 000630: Detection of the Optical Afterglow
  85. GRB000630, Revised BVRI Field Photometry
  86. GRB000630, Optical Observations
  87. GRB000630: Optical observations
  88. possible optical counterpart of GRB 000630
  89. IPN triangulation of GRB000630
  90. GRB 000408, optical observations
  91. Radio observations of the error box of GRB000301A
  92. GRB000301A [IPN Position]
  93. GRB000226 [IPN Position]
  94. IPN localization of GRB991226
  95. GRB991216 Optical and infrared observations of Beethoven Burst
  96. GRB991216 ('Beethoven Burst') B, R, and K Observations
  97. IPN localization of GRB991208
  98. IPN localization of GRB991105
  99. IPN localization of GRB991014 - CORRECTION
  100. IPN localization of GRB991014

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