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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').
Advanced Search

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.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

19861 results found.

  1. GRB011211, BVRI field photometry
  2. Fading of the optical source associated of XRF 011211
  3. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  4. GRB011130 (XRF011130) Chandra Observations
  5. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  6. GRB 011130: Magellan spectroscopy
  7. Sub-mm and Centimeter Detections of the Host Galaxy of GRB000418
  8. GRB 011130, K band observations
  9. GRB011130, optical observations
  10. GRB011130 (XRF011130) SDSS PT i-band observations
  11. XRF011130: Infrared Observations
  12. GRB011130 (=XRF011130): Revised Localization of an X-ray
  13. GRB 011121
  14. GRB 011121: J-band observations
  15. GRB 011121: NIR observations, host galaxy?
  16. GRB010921 - Milagro GeV/TeV Observations
  17. GRB 011121: HST Scheduled
  18. GRB011121: UBRI Observations
  19. GRB011121
  20. GRB 011121 J-Band Astrometry
  21. GRB 011121: Detection of Bright IR Counterpart
  22. GRB011121: possible redshift, continued decay
  23. GRB 011030: TNG K-band observation
  24. XRF011030: J and K band observations
  25. XRF011030: Chandra Observations
  26. GRB011030: Z-band observations
  27. The X-ray Flash 011030 ('GRB 011030')
  28. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  29. GRB 970828: HST Observations of the Host Galaxy
  30. GRB 000131: HST Detection of the Host Galaxy
  31. GRB 970828: HST Observations of the Host Galaxy
  32. GRB011019: Subaru Optical Observations
  33. GRB011030 - further refinement WFC position
  34. GRB011030: radio search
  35. GRB 010921: Possible supernova component
  36. GRB010921, optical observation at early time
  37. GRB 010921, I-band observations
  38. GRB011019, optical observations
  39. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  40. GRB010921: Spectroscopy of the Host Galaxy
  41. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  42. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  43. GRB010923 as seen by BeppoSAX GRBM
  44. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  45. GRB010921, negative optical observations
  46. GRB010921 field photometry
  47. GRB010921 Optical Observations
  48. HETE Trigger #1760 (GRB 010920B?): a new optical source
  49. GRB000926, Host Galaxy Observations
  50. GRB001109, Host Galaxy Spectroscopic Observations
  51. GRB 010222: HST observations -- host galaxy and late-time decay
  52. BeppoSAX/GRBM detection of GRB 010801
  53. GCN and HETE status
  54. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  55. GRB 010222 - WHT BVRI images
  56. GRB 010629 Optical Observations
  57. GRB010629: Optical Observations
  58. SGR1900+14: High Fluence Burst Localized by HETE
  59. GRB010629, optical observations
  60. GRB010629: A Burst Localized by HETE
  61. SGR1900+14: Second Burst Localized by HETE
  62. SGR1900+14: A Burst Localized by HETE
  63. SGR1806-20: A Second, Intense Burst Localized by HETE
  64. SGR1806-20: Localization by HETE
  65. IPN triangulation of GRB010613
  66. HETE Fully-Automated GCN Notices
  67. GRB000301C: Late-time HST/STIS observation
  68. GRB010518: a faint BeppoSAX detection
  69. GRB000418: HST/STIS Second-epoch Observations
  70. X-ray precursors to the large flare from SGR 1900+14
  71. SGR 1900+14 : RXTE observations
  72. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  73. Millimeter observation of SGR 1900+14
  74. SGR 1900+14, Chandra observations
  75. Chandra Observations of SGR 1900+14
  76. SGR1900+14, I-band observations
  77. IPN Triangulation of the Giant Flare from SGR1900+14
  78. GRB010412, field photometry
  79. Giant flare from SGR1900+14
  80. GRB 010326b Optical Observations
  81. GRB010412: BeppoSAX GRBM and WFC observations
  82. GRB010324, revised field photometry
  83. GRB 980326: Late-time HST/STIS observations
  84. GRB010324, field photometry
  85. GRB010326B, field photometry
  86. GRB010326, field photometry
  87. GRB010220, field photometry
  88. Further Optical Observations of GRB 010324
  89. GRB010222, CXO X-ray observations
  90. GRB010324, optical observations
  91. GRB010326B: Localization by HETE (2nd GRB for this date)
  92. GRB 010326 optical observations
  93. GRB010326: Refined Localization by HETE
  94. GRB010326: Localization by HETE
  95. Optical Observations of GRB 010324
  96. GRB010222, late-time optical observation
  97. Support extension to the BeppoSAX mission
  98. GRB 010222 - HEGRA GeV/TeV Observations
  99. GRB010222 - Optical observation
  100. GRB 010222, Optical Observations

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