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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"

3821 results found.

  1. Short RXTE/ASM transient 020406; may be a GRB
  2. XRF/GRB 011030: Detection of the Probable Host Galaxy
  3. IPN detection and localization of Cygnus X-1 flares
  4. RXTE Observations of SGR 1900+14
  5. SGR1900+14 activity
  6. IPN/HETE Detection of Bursts from SGR1900+14
  7. IPN Upper Limits to a GRB Associated With SN2002ap
  8. IPN detection of further activity from SGR1806-20
  9. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  10. GRB010923 as seen by BeppoSAX GRBM
  11. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  12. Probable SGR or Short Duration GRB Detected by HETE
  13. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  14. GRB 010629 Optical Observations
  15. GRB010629: A Burst Localized by HETE
  16. Possible burst from SGR1806-20
  17. IPN detection of SGR1900+14
  18. X-ray precursors to the large flare from SGR 1900+14
  19. SGR 1900+14: No evidence of extended X-ray emission
  20. SGR 1900+14 : RXTE observations
  21. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  22. SGR1900+14
  23. SGR 1900+14: Correction to GCN 1049
  24. Millimeter observation of SGR 1900+14
  25. SGR 1900+14: Detection of extended X-ray emission
  26. Chandra Observations of SGR 1900+14
  27. SGR 1900+14, Chandra observations
  28. Chandra Observations of SGR 1900+14
  29. SGR1900+14, I-band observations
  30. GRB 980326: Late-time HST/STIS observations
  31. GRB 010214, I-band data
  32. GRB010214 Optical Observation
  33. GRB010126 optical observations
  34. Optical Observations of GRB 001018 at Keck
  35. IPN triangulation of GRB001219
  36. GRB 001109: deep JHK upper limits
  37. IPN TRIANGULATION OF GRB001105
  38. IPN TRIANGULATION OF GRB001020
  39. GRB 000926 Chandra Observation
  40. GRB000926 K'-band Observation
  41. HST/STIS observations of the host galaxy of GRB 980329
  42. SGR 1806-20 burst activity
  43. IPN localization of GRB000730B
  44. IPN localization of GRB000730B
  45. GRB 990510: Possible detection of a host galaxy
  46. GRB 990510 Host Galaxy Discovery
  47. GRB 990712: Late time HST/STIS Observations
  48. GRB 000630: Detection of the Optical Afterglow
  49. GRB000616 [IPN Position]
  50. GRB 000418: Detection of the Host Galaxy
  51. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  52. GRB000529: BeppoSAX WFC position
  53. GRB000528: BeppoSAX GRBM observations
  54. GRB000419 [IPN Position]
  55. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  56. GRB 000326: Optical Observations
  57. GRB 000301C, Optical Observation
  58. GRB000301C
  59. GRB 000301C : Optical Candidate
  60. GRB000226 [IPN Position]
  61. HST Observations of GRB 990712
  62. IPN annulus for GRB000214
  63. GRB000126, optical observations
  64. IPN localization of GRB000126
  65. GRB991216 late optical observation
  66. BEPPOSAX GRBM Localization of GRB991226
  67. IPN error boxes for GRB991229
  68. IPN localization of GRB991226
  69. IPN localization of GRB991208
  70. IPN localization of GRB991014 - CORRECTION
  71. IPN localization of GRB991014
  72. BATSE GRB trigger criteria
  73. GRB 990712 Late Optical Decay and Host Galaxy
  74. GRB 990712, Optical Observation
  75. GRB 990712
  76. IPN localization of GRB990705
  77. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  78. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  79. GRB 990510: optical observations
  80. GRB 990510: optical observations
  81. GRB990510: X-ray afterglow
  82. GRB 990510: optical observation
  83. GRB 990510: Broad Band Break
  84. GRB990510: optical observation
  85. GRB 990510 Optical Observations
  86. GRB 990510 optical observations
  87. GRB990510 optical observations
  88. GRB990510
  89. GRB 990510 optical observations
  90. GRB 990510 optical observations
  91. GRB 990510 optical observations
  92. IPN localization of GRB990510
  93. New IPN/RXTE error box for GRB990506
  94. GRB990308 not a new SGR
  95. GRB990308, Possible new SGR~0209+70
  96. GRB 990123: Discovery of the Probable Host Galaxy
  97. Possible identification of SN1999E with GRB980910
  98. GRB 981226: radio variable
  99. GRB 981226 Optical Observations
  100. GRB981226, sub-millimeter observations

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