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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"

5155 results found.

  1. GRB021004, Optical Observations
  2. GRB 021004: Optical Photometry at 1.5 Days
  3. GRB 021004, SPM optical observations
  4. GRB 021004: steepening of the optical decay slope
  5. GRB021004: Upper limits from recent and historical observations
  6. XRF 020903: Supernova
  7. IPN annulus for GRB020923
  8. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  9. INTEGRAL GRBs added to GCN
  10. GRB 020812: early time optical observation at Ouda Station
  11. GRB020813: optical and NIR observations
  12. GRB 020813: addendum to GCN 1498
  13. GRB020812: NIR observations
  14. GRB020813, optical observations
  15. Further refinement to IPN error box for GRB020531
  16. GRB020625 (=H2081): A Long Burst Localized by HETE
  17. GRB020531: Second epoch Chandra observations
  18. GRB020531 Optical observations with TAROT
  19. GRB020531: Observations with the Chandra X-ray Observatory
  20. Refined IPN error box for GRB020531
  21. IPN triangulation of the short, hard GRB020531 (=H2042)
  22. GRB020321 : Optical observations.
  23. GRB 020124: Optical observations
  24. GRB 020409: Optical observations
  25. GRB 020409: No Evidence for an Optical Afterglow
  26. GRB 020331 Kyoto observation on March 31
  27. GRB 020409
  28. GRB020124 optical observations with RIBOTS/RIMOTS
  29. Short RXTE/ASM transient 020406; may be a GRB
  30. GRB 020321, Radio Observations
  31. GRB 020321: Optical observations
  32. GRB 020322 optical observations
  33. GRB020317 : Near IR Observations from Mt Abu Observatory
  34. GRB 020317 : KISO Optical Observations
  35. GRB 020317: Optical observations
  36. GRB011130 (XRF011130) Second Epoch Chandra Observations
  37. IPN detection and localization of Cygnus X-1 flares
  38. IPN Upper Limits to a GRB Associated With SN2002ap
  39. GRB020124: Optical observations
  40. GRB 020124: Optical observations
  41. GRB020124(=H1896): Localization of a Long GRB by HETE
  42. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  43. GRB 011121
  44. GRB011030, optical observation
  45. GRB010923 as seen by BeppoSAX GRBM
  46. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  47. GRB001109, Host Galaxy Astrometry
  48. GRB000926, Host Galaxy Observations
  49. GRB001109, Host Galaxy Spectroscopic Observations
  50. BeppoSAX/GRBM detection of GRB010728
  51. SGR1900+14: Second Burst Localized by HETE
  52. SGR1900+14: A Burst Localized by HETE
  53. Millimeter observation of SGR 1900+14
  54. GRB010324: BeppoSAX/GRBM data
  55. GRB 010214, I-band data
  56. Sub-millimeter Excess/GRB 010222
  57. GRB 010220: Near-IR Observations
  58. GRB 010222: Near-IR Observations
  59. GRB010214, optical observations
  60. J-Band Observation of GRB 010214.
  61. Possible InfraRed Transient of GRB 010214.
  62. GRB010214 Optical Observation
  63. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  64. IPN triangulation of GRB001219
  65. GRB 001212 Optical Observation
  66. GRB 001212 Optical Observation
  67. IPN triangulation of GRB001212
  68. GRB 001025B, I-band observations
  69. IPN TRIANGULATION OF GRB001020
  70. GRB 000926 : the host galaxy
  71. IPN triangulation of GRB001005
  72. J and K band observations of GRB 000926
  73. GRB000830, TNG B-band observations
  74. GRB000830: Optical observations
  75. Updated IPN coordinates for GRB000801
  76. IPN localization of GRB000801
  77. IPN localization of GRB000727
  78. GRB 990712: Late time HST/STIS Observations
  79. GRB000630: Optical observations
  80. GRB 000620: J-band observations
  81. GRB 000615: NIR further observations
  82. GRB 000615: NIR observations
  83. GRB000615: BeppoSAX GRB Alert
  84. IPN localization of GRB000429
  85. GRB000418, near-infrared observations
  86. BeppoSAX GRB000424
  87. IPN error box for GRB000418
  88. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  89. Budget cuts in BeppoSAX operations: impact on GRB observations
  90. GRB000408 [IPN Position]
  91. GRB000301C - B and R photometry
  92. GRB 000301C: HST/STIS CCD Imaging of the field
  93. HST Observations of GRB 990712
  94. SAX_WFC_GRB_NOTICE
  95. GRB 000131 Optical Observations
  96. IPN error boxes for GRB991229
  97. IPN error box for GRB991216
  98. GRB991216, optical observations
  99. GRB991208, optical observations
  100. GRB 991106, optical observations

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