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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"

35436 results found.

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

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