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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"

20958 results found.

  1. GRB 011030 I-band Observations
  2. GRB 011030 K-band Observations
  3. GRB010921, optical observations
  4. GRB 011030, WSRT radio observations
  5. GRB 011030, Radio observations
  6. GRB 011030, R-band observations
  7. GRB011019: NEAT Optical Observations
  8. GRB011019: ROTSE-III optical observations
  9. GRB 010921, I-band observations
  10. GRB011019: Optical observations
  11. GRB011019, optical observations -- correction
  12. GRB011019, optical observations
  13. GRB 010921: The afterglow of HETE #1761
  14. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  15. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  16. GRB010928(=H1770): Localization of a Long GRB by HETE
  17. GRB010921, negative optical observations
  18. GRB010921 Optical Observations
  19. HETE Trigger #1760 (GRB 010920B?): a new optical source
  20. HETE Trigger #1759 (GRB 010920?) optical observations
  21. GRB000926, Host Galaxy Observations
  22. GRB001109, Host Galaxy Spectroscopic Observations
  23. GRB000926 Host Galaxy Observations
  24. GRB 010222: HST observations -- host galaxy and late-time decay
  25. GRB 010222 - WHT BVRI images
  26. GRB 010629 Optical Observations
  27. GRB010629: Optical Observations
  28. SGR1900+14: High Fluence Burst Localized by HETE
  29. GRB010629, optical observations
  30. GRB010629: A Burst Localized by HETE
  31. SGR1900+14: Second Burst Localized by HETE
  32. SGR1900+14: A Burst Localized by HETE
  33. SGR1806-20: A Second, Intense Burst Localized by HETE
  34. GRB 00630: Host Galaxy
  35. SGR1806-20: Localization by HETE
  36. GRB000301C: Late-time HST/STIS observation
  37. GRB000418: HST/STIS Second-epoch Observations
  38. GRB010214, optical observations
  39. GRB010427, Gamma Ray Observations
  40. SGR 1900+14: No evidence of extended X-ray emission
  41. SGR 1900+14 : RXTE observations
  42. GRB 010222 /corrections to VBT data
  43. Millimeter observation of SGR 1900+14
  44. Chandra Observations of SGR 1900+14
  45. SGR 1900+14, Chandra observations
  46. Chandra Observations of SGR 1900+14
  47. SGR1900+14, I-band observations
  48. GRB 010326b Optical Observations
  49. GRB010412: Optical observations
  50. GRB010412: Optical observations
  51. GRB010412: BeppoSAX GRBM and WFC observations
  52. GRB Observation Report
  53. GRB 980326: Late-time HST/STIS observations
  54. Further Optical Observations of GRB 010324
  55. GRB010222, CXO X-ray observations
  56. GRB 010326A: Further optical observations
  57. GRB 010326B: Optical observations
  58. GRB010324, optical observations
  59. GRB010326B: Localization by HETE (2nd GRB for this date)
  60. GRB 010326: Optical observations
  61. GRB 010326 optical observations
  62. GRB010326: Refined Localization by HETE
  63. GRB010326: Localization by HETE
  64. Optical Observations of GRB 010324
  65. IPN TRIANGULATION OF GRB010324
  66. GRB990705, VLT-FORS1 observations of the host galaxy
  67. GRB 010222 - HEGRA GeV/TeV Observations
  68. GRB010222: Sub-millimeter vanishing act
  69. GRB 010222, Optical Observations
  70. Sub-millimeter Excess/GRB 010222
  71. GRB 010222
  72. GRB 010222 HST/Chandra TOO
  73. GRB010222 further R-band photometry
  74. GRB010222 Optical observations
  75. GRB010222, field photometry
  76. GRB010222 further R-band photometry
  77. GRB010222, possible increase of optical decay slope
  78. GRB 010222 BV optical observations
  79. GRB010220, Optical Observations
  80. GRB010222 R-BAND OBSERVATION
  81. GRB 010220: Near-IR Observations
  82. GRB010214 follow-up from Hanle
  83. GRB 010222: Near-IR Observations
  84. GRB 010222: Optical Observations
  85. GRB010222: Optical decay slope
  86. GRB 010214, Optical Observations
  87. GRB010222: Sub-millimeter detection
  88. GRB010222: R-band fading behavior
  89. GRB010222: Optical Observations
  90. GRB010222, radio observations
  91. GRB010222, optical observations
  92. GRB010222: BeppoSAX/NFI Observations
  93. GRB010214B,Gamma Ray Observations
  94. GRB010222
  95. GRB010220, Radio and Optical Observations
  96. GRB 010220, simultaneous optical observations
  97. GRB010214, candidate optical afterglow
  98. GRB010214, optical observations
  99. GRB 010214, Optical Observations
  100. GRB010213, Radio Observations

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