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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"

22062 results found.

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

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