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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"

20564 results found.

  1. GRB 010222 /corrections to VBT data
  2. Millimeter observation of SGR 1900+14
  3. Chandra Observations of SGR 1900+14
  4. SGR 1900+14, Chandra observations
  5. Chandra Observations of SGR 1900+14
  6. SGR1900+14, I-band observations
  7. GRB 010326b Optical Observations
  8. GRB010412: Optical observations
  9. GRB010412: Optical observations
  10. GRB010412: BeppoSAX GRBM and WFC observations
  11. GRB Observation Report
  12. GRB 980326: Late-time HST/STIS observations
  13. Further Optical Observations of GRB 010324
  14. GRB010222, CXO X-ray observations
  15. GRB 010326A: Further optical observations
  16. GRB 010326B: Optical observations
  17. GRB010324, optical observations
  18. GRB010326B: Localization by HETE (2nd GRB for this date)
  19. GRB 010326: Optical observations
  20. GRB 010326 optical observations
  21. GRB010326: Refined Localization by HETE
  22. GRB010326: Localization by HETE
  23. Optical Observations of GRB 010324
  24. IPN TRIANGULATION OF GRB010324
  25. GRB990705, VLT-FORS1 observations of the host galaxy
  26. GRB010222, late-time optical observation
  27. GRB 010222 - HEGRA GeV/TeV Observations
  28. GRB010222: Sub-millimeter vanishing act
  29. GRB 010222, Optical Observations
  30. GRB 010222: High-Resolution Keck Spectroscopy
  31. GRB 010214, I-band data
  32. Sub-millimeter Excess/GRB 010222
  33. GRB 010222
  34. GRB 010222 HST/Chandra TOO
  35. GRB010222 further R-band photometry
  36. GRB010222 Optical observations
  37. GRB010222, field photometry
  38. GRB010222 further R-band photometry
  39. GRB010222, possible increase of optical decay slope
  40. GRB 010222 BV optical observations
  41. GRB010220, Optical Observations
  42. GRB010222 R-BAND OBSERVATION
  43. GRB 010220: Near-IR Observations
  44. GRB010214 follow-up from Hanle
  45. GRB 010222: Near-IR Observations
  46. GRB 010222: Optical Observations
  47. GRB010222: Optical decay slope
  48. GRB 010214, Optical Observations
  49. GRB010222: Sub-millimeter detection
  50. GRB010222: R-band fading behavior
  51. GRB010222: Optical Observations
  52. GRB010222, radio observations
  53. GRB010222, optical observations
  54. GRB010222: BeppoSAX/NFI Observations
  55. Redshift of the Optical Transient of GRB010222
  56. GRB010214B,Gamma Ray Observations
  57. GRB010222
  58. GRB010220, Radio and Optical Observations
  59. GRB 010220, simultaneous optical observations
  60. GRB010214, candidate optical afterglow
  61. GRB010214, optical observations
  62. GRB 010214, Optical Observations
  63. GRB010213, Radio Observations
  64. GRB010213 Optical Observation
  65. GRB010213, Radio Observations
  66. J-Band Observation of GRB 010214.
  67. GRB010214, Radio Observations
  68. GRB010214, optical observations
  69. GRB010213, optical observations
  70. GRB010213, Near-IR observations
  71. Possible InfraRed Transient of GRB 010214.
  72. GRB010214 Optical Observation
  73. GRB010214: BeppoSAX/NFI Observations
  74. GRB010213 (HETE) TAROT observations
  75. GRB 010214, optical observations
  76. GRB010213 detected by HETE
  77. GRB010126, TNG R-band observations
  78. GRB010126 Optical Observations
  79. GRB010126 optical observations
  80. GRB010126: Optical observations
  81. GRB 010119, optical observations
  82. GRB010119: Optical observations
  83. Optical Observations of GRB 001018 at Keck
  84. GRB010119, Radio observations
  85. Optical observations of GRB 001018 with JCAM
  86. GRB010103, optical observations
  87. GRB 001204: Ks observations
  88. H band observation of GRB 001212
  89. GRB 001212 possible OA
  90. GRB001204: Optical observations
  91. GRB001204, Radio observations
  92. GRB 001105, further optical observations
  93. GRB001120: Gunn-i observations
  94. GRB001120: Optical observations
  95. GRB001109, optical observations
  96. GRB001120, optical observations
  97. WSRT 4.8 GHz observations of GRB001109
  98. Optical/NIR observations of GRB001109
  99. GRB 001109: deep JHK upper limits
  100. GRB001109: Optical observations

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