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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"

35431 results found.

  1. GRB 011211 Optical Observations: Likely Afterglow
  2. BeppoSAX Alert: GRB011211(=XRF011211)
  3. GRB 011130: Optical Observations of Chandra Sources
  4. GRB 011130: Optical Observations of Chandra sources
  5. GRB 011130: Magellan spectroscopy
  6. Sub-mm and Centimeter Detections of the Host Galaxy of GRB000418
  7. GRB011130, optical observations
  8. GRB 011130, K band observations
  9. GRB011130, optical observations
  10. GRB 011130 I-band Observation
  11. GRB011130 (XRF011130) optical observations
  12. GRB011130 (XRF011130) SDSS PT i-band observations
  13. Detection of the X-ray afterglow of GRB011121 by BeppoSAX
  14. XRF011130: NEAT Optical Observations
  15. GRB011130 (=XRF011130): Revised Localization of an X-ray
  16. GRB001109, Radio Monitoring
  17. GRB 011121: Errata URL
  18. GRB 011121
  19. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  20. GRB 011121: J-band observations
  21. GRB 011121: NIR observations, host galaxy?
  22. GRB 011121: HST Scheduled
  23. GRB011121: fainter still
  24. Correction: GCN1157 (GRB 011121)
  25. GRB 011121: Radio Observations
  26. GRB 011121 J-Band Astrometry
  27. GRB011121: continued decay
  28. GRB 011121: Detection of Bright IR Counterpart
  29. GRB011121: possible redshift, continued decay
  30. IPN triangulation of GRB011121
  31. BEPPOSAX GRB011121
  32. GRB 011030: TNG K-band observation
  33. XRF011030: Chandra Observations
  34. GRB 011030: K-band observations
  35. GRB 011030 R band observations
  36. GRB 011030 I-band Observation
  37. The X-ray Flash 011030 ('GRB 011030')
  38. Non-triggered burst 011030 ("GRB 011030")
  39. The Radio Afterglow from the X-ray Rich GRB 011030
  40. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  41. GRB 970828: HST Observations of the Host Galaxy
  42. GRB 000131: HST Detection of the Host Galaxy
  43. GRB 970828: HST Observations of the Host Galaxy
  44. GRB010921, optical observation
  45. GRB 011019 optical observation
  46. GRB011019: Subaru Optical Observations
  47. GRB 011030 I-band Observations
  48. GRB 011030 K-band Observations
  49. GRB010921, optical observations
  50. GRB 011030, WSRT radio observations
  51. GRB011030 - further refinement WFC position
  52. GRB 011030, Radio observations
  53. GRB 011030, R-band observations
  54. BeppoSAX ALERT: Possible X-ray rich GRB011030
  55. GRB 010921: Possible supernova component
  56. GRB011019: NEAT Optical Observations
  57. GRB010921, optical observation at early time
  58. GRB 010921, I-band observations
  59. GRB011019: Optical observations
  60. GRB011019, optical observations
  61. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  62. GRB010921: Spectroscopy of the Host Galaxy
  63. GRB 010921: The afterglow of HETE #1761
  64. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  65. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  66. GRB010923 as seen by BeppoSAX GRBM
  67. GRB010928(=H1770): Localization of a Long GRB by HETE
  68. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  69. GRB010921, negative optical observations
  70. GRB010921 field photometry
  71. GRB010921 Optical Observations
  72. GRB 010921 DPOSS Images Available
  73. IPN triangulation of GRB010921 (=H1761)
  74. H1761: A Bright GRB Detected by HETE
  75. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  76. HETE Trigger #1760 (GRB 010920B?): a new optical source
  77. HETE Trigger #1759 (GRB 010920?) optical observations
  78. GRB001109, Host Galaxy Astrometry
  79. GRB000926, Host Galaxy Observations
  80. GRB001109, Host Galaxy Spectroscopic Observations
  81. Probable SGR or Short Duration GRB Detected by HETE
  82. GRB000926 Host Galaxy Observations
  83. GRB 010222: HST observations -- host galaxy and late-time decay
  84. BeppoSAX/GRBM detection of GRB 010801
  85. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  86. GRB 010222 - WHT BVRI images
  87. GRB 010629 Optical Observations
  88. GRB010629: Optical Observations
  89. GRB010629, optical observations
  90. IPN triangulation of GRB010629
  91. GRB010629: A Burst Localized by HETE
  92. Possible burst from SGR1806-20
  93. IPN detection of SGR1900+14
  94. GRB 00630: Host Galaxy
  95. IPN triangulation of GRB010613
  96. IPN triangulation of GRB010612
  97. HETE Fully-Automated GCN Notices
  98. GRB000301C: Late-time HST/STIS observation
  99. GRB010518: a faint BeppoSAX detection
  100. GRB000418: HST/STIS Second-epoch Observations

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