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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"

35441 results found.

  1. optical follow-up of GRB(XRF) 011211
  2. GRB 011212: optical observation at Oslo (relayed)
  3. GRB 011211: Optical Spectroscopy
  4. GRB 011211, Optical Observations
  5. GRB011212, BVRI field photometry
  6. GRB011211, BVRI field photometry
  7. GRB011212: Optical observations
  8. GRB 011211: BVRi-band photometry
  9. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  10. Fading of the optical source associated of XRF 011211
  11. GRB 011211 Optical Observations: Likely Afterglow
  12. BeppoSAX Alert: GRB011211(=XRF011211)
  13. GRB 011130: Optical Observations of Chandra Sources
  14. GRB 011130: Optical Observations of Chandra sources
  15. GRB 011130: Magellan spectroscopy
  16. Sub-mm and Centimeter Detections of the Host Galaxy of GRB000418
  17. GRB011130, optical observations
  18. GRB 011130, K band observations
  19. GRB011130, optical observations
  20. GRB 011130 I-band Observation
  21. GRB011130 (XRF011130) optical observations
  22. GRB011130 (XRF011130) SDSS PT i-band observations
  23. Detection of the X-ray afterglow of GRB011121 by BeppoSAX
  24. XRF011130: NEAT Optical Observations
  25. GRB011130 (=XRF011130): Revised Localization of an X-ray
  26. GRB001109, Radio Monitoring
  27. GRB 011121: Errata URL
  28. GRB 011121
  29. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  30. GRB 011121: J-band observations
  31. GRB 011121: NIR observations, host galaxy?
  32. GRB 011121: HST Scheduled
  33. GRB011121: fainter still
  34. Correction: GCN1157 (GRB 011121)
  35. GRB 011121: Radio Observations
  36. GRB 011121 J-Band Astrometry
  37. GRB011121: continued decay
  38. GRB 011121: Detection of Bright IR Counterpart
  39. GRB011121: possible redshift, continued decay
  40. IPN triangulation of GRB011121
  41. BEPPOSAX GRB011121
  42. GRB 011030: TNG K-band observation
  43. XRF011030: Chandra Observations
  44. GRB 011030: K-band observations
  45. GRB 011030 R band observations
  46. GRB 011030 I-band Observation
  47. The X-ray Flash 011030 ('GRB 011030')
  48. Non-triggered burst 011030 ("GRB 011030")
  49. The Radio Afterglow from the X-ray Rich GRB 011030
  50. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  51. GRB 970828: HST Observations of the Host Galaxy
  52. GRB 000131: HST Detection of the Host Galaxy
  53. GRB 970828: HST Observations of the Host Galaxy
  54. GRB010921, optical observation
  55. GRB 011019 optical observation
  56. GRB011019: Subaru Optical Observations
  57. GRB 011030 I-band Observations
  58. GRB 011030 K-band Observations
  59. GRB010921, optical observations
  60. GRB 011030, WSRT radio observations
  61. GRB011030 - further refinement WFC position
  62. GRB 011030, Radio observations
  63. GRB 011030, R-band observations
  64. BeppoSAX ALERT: Possible X-ray rich GRB011030
  65. GRB 010921: Possible supernova component
  66. GRB011019: NEAT Optical Observations
  67. GRB010921, optical observation at early time
  68. GRB 010921, I-band observations
  69. GRB011019: Optical observations
  70. GRB011019, optical observations
  71. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  72. GRB010921: Spectroscopy of the Host Galaxy
  73. GRB 010921: The afterglow of HETE #1761
  74. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  75. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  76. GRB010923 as seen by BeppoSAX GRBM
  77. GRB010928(=H1770): Localization of a Long GRB by HETE
  78. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  79. GRB010921, negative optical observations
  80. GRB010921 field photometry
  81. GRB010921 Optical Observations
  82. GRB 010921 DPOSS Images Available
  83. IPN triangulation of GRB010921 (=H1761)
  84. H1761: A Bright GRB Detected by HETE
  85. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  86. HETE Trigger #1760 (GRB 010920B?): a new optical source
  87. HETE Trigger #1759 (GRB 010920?) optical observations
  88. GRB001109, Host Galaxy Astrometry
  89. GRB000926, Host Galaxy Observations
  90. GRB001109, Host Galaxy Spectroscopic Observations
  91. Probable SGR or Short Duration GRB Detected by HETE
  92. GRB000926 Host Galaxy Observations
  93. GRB 010222: HST observations -- host galaxy and late-time decay
  94. BeppoSAX/GRBM detection of GRB 010801
  95. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  96. GRB 010222 - WHT BVRI images
  97. GRB 010629 Optical Observations
  98. GRB010629: Optical Observations
  99. GRB010629, optical observations
  100. IPN triangulation of GRB010629

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