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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"

5157 results found.

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

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