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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"

14824 results found.

  1. GRB 020625, optical observations
  2. GRB/XRF 020427, detection of an underlying system with the VLT
  3. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  4. AXP 1E2259+586: quasi-simultaneous optical observation
  5. AXP 1E2259+586 optical observations
  6. GRB 020531, simultaneous optical observations
  7. GRB020531: Detection of Candidate Host Galaxy
  8. GRB020531: Upper Limit for Detection of Two TAROT Sources
  9. IPN detection of possible bursts from SGR1806-20
  10. HETE Observations of GX354-0 (= MXB1728-34, so-called "Slow
  11. HST detection of the likely host galaxy of GRB 020124
  12. The end of BSAX GRB activities
  13. GRB 020124: Optical observations
  14. GRB020410: BeppoSAX NFI observations refined analysis
  15. Mars Odyssey joins the IPN
  16. GRB020405: predicted break
  17. GRB 020409, No Optical Detection to R = 22
  18. GRB 020331 Kyoto observation on March 31
  19. GRB 020409
  20. GRB 020409, No Optical Detection to R = 20
  21. X-ray afterglow of GRB020321
  22. ASM GRB candidate 020406 refined error box
  23. GRB020331: Optical Observations of Afterglow Candidate
  24. GRB020406(?), optical observations
  25. GRB 020405, U-band observations
  26. GRB011212: Optical Observations
  27. GRB 020322: Optical Observations
  28. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  29. GRB 020322 optical observation
  30. GRB020322, optical observations
  31. GRB020321: BeppoSAX/NFI Observations
  32. GRB020321: a faint BeppoSAX detection
  33. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  34. GRB020317, optical observations
  35. GRB 011121: HST Observations reveal an intermediate-time multicolor
  36. XRF/GRB 011030: Detection of the Probable Host Galaxy
  37. GRB020305 (=H1939): Localization of a GRB by HETE
  38. IPN detection and localization of Cygnus X-1 flares
  39. GRB020127: Further VLA Observations of Possible Counterparts
  40. IPN detection of further SGR1900+14 activity
  41. IPN/HETE Detection of Bursts from SGR1900+14
  42. GRB020127: Palomar and VLA Observations of Possible Counterparts
  43. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  44. Type Ib/c SN2002ap (SN/GRB?)
  45. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  46. IPN detection of further activity from SGR1806-20
  47. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  48. GRB020124(=H1896): Localization of a Long GRB by HETE
  49. GRB 011211: Detection of the Probable Host Galaxy
  50. GRB 011211: Evidence for an Optical Break
  51. GRB 011211: TNG Spectroscopic Observations
  52. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  53. Sub-mm and Centimeter Detections of the Host Galaxy of GRB000418
  54. GRB 011130, K band observations
  55. Detection of the X-ray afterglow of GRB011121 by BeppoSAX
  56. GRB011130 (=XRF011130): Revised Localization of an X-ray
  57. GRB 011121: J-band observations
  58. GRB 011121: Detection of Bright IR Counterpart
  59. GRB 011030 I-band Observation
  60. The X-ray Flash 011030 ('GRB 011030')
  61. The Radio Afterglow from the X-ray Rich GRB 011030
  62. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  63. GRB 000131: HST Detection of the Host Galaxy
  64. GRB 011030 K-band Observations
  65. GRB011019: ROTSE-III optical observations
  66. GRB010928(=H1770): Localization of a Long GRB by HETE
  67. BeppoSAX/GRBM detection of GRB 010801
  68. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  69. BeppoSAX/GRBM detection of GRB010728
  70. SGR1900+14: High Fluence Burst Localized by HETE
  71. GRB010629: A Burst Localized by HETE
  72. SGR1900+14: Second Burst Localized by HETE
  73. SGR1900+14: A Burst Localized by HETE
  74. IPN detection of SGR1900+14
  75. SGR1806-20: A Second, Intense Burst Localized by HETE
  76. SGR1806-20: Localization by HETE
  77. GRB000301C: Late-time HST/STIS observation
  78. GRB010518: a faint BeppoSAX detection
  79. GRB000418: HST/STIS Second-epoch Observations
  80. SGR 1900+14: No evidence of extended X-ray emission
  81. SGR 1900+14: Detection of extended X-ray emission
  82. GRB 010222: High-Resolution Keck Spectroscopy
  83. GRB 010214, I-band data
  84. GRB 010222 Kyoto optical observation
  85. GRB010214 follow-up from Hanle
  86. GRB010222: Sub-millimeter detection
  87. GRB010222: Optical Observations
  88. GRB010222: possible optical counterpart
  89. GRB010220, Radio and Optical Observations
  90. GRB010213 Optical Observation
  91. GRB010213, Radio Observations
  92. GRB010214 Optical Observation
  93. IPN Status Report
  94. HETE Status
  95. GRB010126 opt. obs.
  96. GRB010126: CONCAM crude optical limits during GRB
  97. GRB010126 optical observations
  98. Optical Observations of GRB 001018 at Keck
  99. GRB 001212 Optical Observation
  100. Confirmation of IPN position for GRB001204

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