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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"

41687 results found.

  1. GRB011211: BeppoSAX/GRBM data
  2. Optical polarization observations for GRB011211
  3. GRB 011211: Detection of the Probable Host Galaxy
  4. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  5. Color indices of the afterglow of GRB011211
  6. GRB011212: Optical observations at Gunma
  7. GRB 011211, spectrum and optical photometry
  8. GRB 011130: Optical Observations of X-ray and Radio Sources
  9. GRB 011130, Radio/X-ray Comparison
  10. GRB011212: Optical observations
  11. GRB 011212: optical observation at Asiago
  12. GRB 011211: Evidence for an Optical Break
  13. GRB 011211: TNG Spectroscopic Observations
  14. optical follow-up of GRB(XRF) 011211
  15. GRB 011212: optical observation at Oslo (relayed)
  16. GRB 011211: Optical Spectroscopy
  17. GRB 011211, Optical Observations
  18. GRB011212, BVRI field photometry
  19. GRB011211, BVRI field photometry
  20. GRB011212: Optical observations
  21. GRB 011211: BVRi-band photometry
  22. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  23. Fading of the optical source associated of XRF 011211
  24. XMM-Newton observation of GRB011211
  25. GRB 011211 Optical Observations: Likely Afterglow
  26. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  27. BeppoSAX Alert: GRB011211(=XRF011211)
  28. GRB 011130: Optical Observations of Chandra Sources
  29. GRB 011130: Optical Observations of Chandra sources
  30. GRB011130 (XRF011130) Chandra Observations
  31. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  32. GRB 011130: Magellan spectroscopy
  33. Sub-mm and Centimeter Detections of the Host Galaxy of GRB000418
  34. GRB011130, optical observations
  35. GRB 011130, K band observations
  36. GRB011130, optical observations
  37. GRB011130 (=XRF011130): Second Revised Localization by HETE
  38. GRB 011130 I-band Observation
  39. GRB011130 (XRF011130) optical observations
  40. GRB011130 (XRF011130) SDSS PT i-band observations
  41. XRF011130: Infrared Observations
  42. GRB011130, Radio Observations
  43. Detection of the X-ray afterglow of GRB011121 by BeppoSAX
  44. GRB011130 (=XRF011130), Optical Observations
  45. XRF011130: NEAT Optical Observations
  46. GRB011130 (=XRF011130): Revised Localization of an X-ray
  47. GRB001109, Radio Monitoring
  48. GRB 011121: Errata URL
  49. GRB 011121
  50. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  51. GRB 011121: J-band observations
  52. GRB 011121: NIR observations, host galaxy?
  53. GRB010921 - Milagro GeV/TeV Observations
  54. GRB 011121: HST Scheduled
  55. GRB011121: fainter still
  56. Correction: GCN1157 (GRB 011121)
  57. GRB011121: UBRI Observations
  58. GRB011121
  59. GRB 011121: Radio Observations
  60. GRB 011121 J-Band Astrometry
  61. GRB011121: continued decay
  62. GRB 011121: Detection of Bright IR Counterpart
  63. GRB011121: possible redshift, continued decay
  64. GRB011121: fading behavior
  65. GRB011121: possible optical counterpart
  66. IPN triangulation of GRB011121
  67. BEPPOSAX GRB011121
  68. GRB 011030: TNG K-band observation
  69. XRF011030: J and K band observations
  70. XRF011030: Chandra Observations
  71. GRB 011030: K-band observations
  72. GRB011030: Z-band observations
  73. GRB 011030 R band observations
  74. GRB 011030 I-band Observation
  75. The X-ray Flash 011030 ('GRB 011030')
  76. Non-triggered burst 011030 ("GRB 011030")
  77. The Radio Afterglow from the X-ray Rich GRB 011030
  78. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  79. GRB 970828: HST Observations of the Host Galaxy
  80. GRB 000131: HST Detection of the Host Galaxy
  81. GRB 970828: HST Observations of the Host Galaxy
  82. GRB010921, optical observation
  83. GRB 011019 optical observation
  84. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  85. GRB011019: Subaru Optical Observations
  86. GRB 011030 I-band Observations
  87. GRB 011030 K-band Observations
  88. GRB010921, optical observations
  89. GRB 011030, WSRT radio observations
  90. GRB011030 - further refinement WFC position
  91. GRB 011030, Radio observations
  92. GRB011030: radio search
  93. GRB 011030, R-band observations
  94. BeppoSAX ALERT: Possible X-ray rich GRB011030
  95. GRB 010921: Possible supernova component
  96. GRB011019: NEAT Optical Observations
  97. GRB011019: ROTSE-III optical observations
  98. GRB010921, optical observation at early time
  99. GRB 010921, I-band observations
  100. GRB011019: Optical observations

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