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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"

24063 results found.

  1. HETE 2493: Optical observations
  2. HETE 2493: Optical candidate
  3. GRB 021204: Optical Observations at RIKEN
  4. GRB 021201: BOOTES simultaneous optical observations
  5. GRB 021112: RAPTOR Observations
  6. GRB021104: Optical Observations
  7. SGR1900+14 activity, November 2-4, 2002
  8. GRB021104: possible optical afterglow
  9. GRB 021016, optical observations
  10. GRB 021004: VRI observations at TNG: possible break
  11. GRB 021008, optical observations
  12. IPN triangulation of GRB021014 (large error box)
  13. GRB 021004: Additional V-band Polarimetric Observations
  14. GRB 021004: V-band Polarimetric Observations
  15. GRB 021004: Optical observations at RIKEN
  16. GRB 021004, SPM optical observations
  17. GRB021004: optical observations at Nyrola
  18. GRB021004: Optical Afterglow
  19. GRB 020903: Optical observations at RIKEN
  20. XRF 020903: Supernova
  21. IPN triangulation of GRB020914
  22. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  23. INTEGRAL GRBs added to GCN
  24. GRB020812: optical observation
  25. Second epoch K band imaging of GRB 020819
  26. K band observation of GRB 020819
  27. HETE 2275: Optical observations
  28. Polarimetry of GRB020813: evidence for variability
  29. GRB020812: optical observations
  30. GRB020813: Early Time Magnitude
  31. GRB020813, optical observations
  32. Early Time Limits for GRB020813
  33. GRB 020813 Afterglow Observations; Possible break
  34. GRB 020813 multiband optical observations
  35. GRB020813: optical afterglow
  36. GRB020813: Fading of Candidate OT
  37. GRB020813: Candidate Optical Afterglow
  38. GRB 020812 optical observation
  39. GRB020801, optical afterglow candidate
  40. GRB020625 (=H2081): A Long Burst Localized by HETE
  41. HETE #2081: Optical observations
  42. GRB 020531, simultaneous optical observations
  43. GRB020321 : Optical observations.
  44. GRB 020410, optical observations
  45. GRB 020331: Candidate Optical Afterglow
  46. GRB 020322: BeppoSAX observations of the X-ray afterglow
  47. SN 2002ap - peak brightness date (SN/GRB?)
  48. GRB020321: a faint BeppoSAX detection
  49. GRB020317, optical observations
  50. GRB020305, optical observations
  51. GRB020124, optical observations
  52. HETE 1896: Optical observations
  53. GRB011130 (=XRF011130), Optical Observations
  54. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  55. GRB 011030: K-band observations
  56. The X-ray Flash 011030 ('GRB 011030')
  57. GRB 011019 optical observation
  58. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  59. GRB 010921: The afterglow of HETE #1761
  60. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  61. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  62. GRB010921 Optical Observations
  63. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  64. HETE Trigger #1760 (GRB 010920B?): a new optical source
  65. HETE Trigger #1759 (GRB 010920?) optical observations
  66. BeppoSAX/GRBM detection of GRB 010801
  67. GCN and HETE status
  68. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  69. GRB 010629 Optical Observations
  70. IPN triangulation of GRB010613
  71. IPN triangulation of GRB010612
  72. GRB010518: a faint BeppoSAX detection
  73. GRB010324: BeppoSAX/GRBM data
  74. GRB 010214: X-Ray afterglow
  75. GRB010213, optical observations
  76. GRB010126: CONCAM crude optical limits during GRB
  77. HETE positions added to GCN
  78. CONCAM null result on GRB001005
  79. CONCAM crude optical limits before and after GRB000926
  80. GRB000607, optical observations
  81. GRB 000615: NIR observations
  82. IPN triangulation of GRB000519
  83. RXTE/ASM and IPN localization of GRB 000508B
  84. BeppoSAX GRB000424
  85. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  86. GRB000408, lotis optical observations
  87. GRB 000313 - optical transient in the BATSE error box
  88. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  89. BATSE GRB trigger criterion changed
  90. GRB000210 X-ray afterglow
  91. GRB 000210: BATSE Observations
  92. GRB000201 Optical Observations
  93. GRB 000201: TAROT optical observations
  94. BATSE GRB trigger criteria changed
  95. BATSE+IPN location of GRB000131
  96. BATSE location of GRB000126
  97. BATSE Observations of GRB000115
  98. Second RXTE Observation of GRB 000115
  99. Single IPN error box for GRB991229
  100. GRB 991216: Updated BATSE parameters

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