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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"

35433 results found.

  1. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  2. Fading of the optical source associated of XRF 011211
  3. GRB 011211 Optical Observations: Likely Afterglow
  4. BeppoSAX Alert: GRB011211(=XRF011211)
  5. GRB 011130: Optical Observations of Chandra Sources
  6. GRB 011130: Optical Observations of Chandra sources
  7. GRB 011130: Magellan spectroscopy
  8. Sub-mm and Centimeter Detections of the Host Galaxy of GRB000418
  9. GRB011130, optical observations
  10. GRB 011130, K band observations
  11. GRB011130, optical observations
  12. GRB 011130 I-band Observation
  13. GRB011130 (XRF011130) optical observations
  14. GRB011130 (XRF011130) SDSS PT i-band observations
  15. Detection of the X-ray afterglow of GRB011121 by BeppoSAX
  16. XRF011130: NEAT Optical Observations
  17. GRB011130 (=XRF011130): Revised Localization of an X-ray
  18. GRB001109, Radio Monitoring
  19. GRB 011121: Errata URL
  20. GRB 011121
  21. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  22. GRB 011121: J-band observations
  23. GRB 011121: NIR observations, host galaxy?
  24. GRB 011121: HST Scheduled
  25. GRB011121: fainter still
  26. Correction: GCN1157 (GRB 011121)
  27. GRB 011121: Radio Observations
  28. GRB 011121 J-Band Astrometry
  29. GRB011121: continued decay
  30. GRB 011121: Detection of Bright IR Counterpart
  31. GRB011121: possible redshift, continued decay
  32. IPN triangulation of GRB011121
  33. BEPPOSAX GRB011121
  34. GRB 011030: TNG K-band observation
  35. XRF011030: Chandra Observations
  36. GRB 011030: K-band observations
  37. GRB 011030 R band observations
  38. GRB 011030 I-band Observation
  39. The X-ray Flash 011030 ('GRB 011030')
  40. Non-triggered burst 011030 ("GRB 011030")
  41. The Radio Afterglow from the X-ray Rich GRB 011030
  42. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  43. GRB 970828: HST Observations of the Host Galaxy
  44. GRB 000131: HST Detection of the Host Galaxy
  45. GRB 970828: HST Observations of the Host Galaxy
  46. GRB010921, optical observation
  47. GRB 011019 optical observation
  48. GRB011019: Subaru Optical Observations
  49. GRB 011030 I-band Observations
  50. GRB 011030 K-band Observations
  51. GRB010921, optical observations
  52. GRB 011030, WSRT radio observations
  53. GRB011030 - further refinement WFC position
  54. GRB 011030, Radio observations
  55. GRB 011030, R-band observations
  56. BeppoSAX ALERT: Possible X-ray rich GRB011030
  57. GRB 010921: Possible supernova component
  58. GRB011019: NEAT Optical Observations
  59. GRB010921, optical observation at early time
  60. GRB 010921, I-band observations
  61. GRB011019: Optical observations
  62. GRB011019, optical observations
  63. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  64. GRB010921: Spectroscopy of the Host Galaxy
  65. GRB 010921: The afterglow of HETE #1761
  66. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  67. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  68. GRB010923 as seen by BeppoSAX GRBM
  69. GRB010928(=H1770): Localization of a Long GRB by HETE
  70. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  71. GRB010921, negative optical observations
  72. GRB010921 field photometry
  73. GRB010921 Optical Observations
  74. GRB 010921 DPOSS Images Available
  75. IPN triangulation of GRB010921 (=H1761)
  76. H1761: A Bright GRB Detected by HETE
  77. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  78. HETE Trigger #1760 (GRB 010920B?): a new optical source
  79. HETE Trigger #1759 (GRB 010920?) optical observations
  80. GRB001109, Host Galaxy Astrometry
  81. GRB000926, Host Galaxy Observations
  82. GRB001109, Host Galaxy Spectroscopic Observations
  83. Probable SGR or Short Duration GRB Detected by HETE
  84. GRB000926 Host Galaxy Observations
  85. GRB 010222: HST observations -- host galaxy and late-time decay
  86. BeppoSAX/GRBM detection of GRB 010801
  87. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  88. GRB 010222 - WHT BVRI images
  89. GRB 010629 Optical Observations
  90. GRB010629: Optical Observations
  91. GRB010629, optical observations
  92. IPN triangulation of GRB010629
  93. GRB010629: A Burst Localized by HETE
  94. Possible burst from SGR1806-20
  95. IPN detection of SGR1900+14
  96. GRB 00630: Host Galaxy
  97. IPN triangulation of GRB010613
  98. IPN triangulation of GRB010612
  99. HETE Fully-Automated GCN Notices
  100. GRB000301C: Late-time HST/STIS observation

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