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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"

20968 results found.

  1. GRB 011030 R band observations
  2. The X-ray Flash 011030 ('GRB 011030')
  3. Non-triggered burst 011030 ("GRB 011030")
  4. The Radio Afterglow from the X-ray Rich GRB 011030
  5. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  6. GRB 970828: HST Observations of the Host Galaxy
  7. GRB 970828: HST Observations of the Host Galaxy
  8. GRB010921, optical observation
  9. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  10. GRB011019: Subaru Optical Observations
  11. GRB 011030 I-band Observations
  12. GRB 011030 K-band Observations
  13. GRB010921, optical observations
  14. GRB 011030, WSRT radio observations
  15. GRB 011030, Radio observations
  16. GRB 011030, R-band observations
  17. GRB011019: NEAT Optical Observations
  18. GRB011019: ROTSE-III optical observations
  19. GRB 010921, I-band observations
  20. GRB011019: Optical observations
  21. GRB011019, optical observations -- correction
  22. GRB011019, optical observations
  23. GRB 010921: The afterglow of HETE #1761
  24. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  25. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  26. GRB010928(=H1770): Localization of a Long GRB by HETE
  27. GRB010921, negative optical observations
  28. GRB010921 Optical Observations
  29. HETE Trigger #1760 (GRB 010920B?): a new optical source
  30. HETE Trigger #1759 (GRB 010920?) optical observations
  31. GRB000926, Host Galaxy Observations
  32. GRB001109, Host Galaxy Spectroscopic Observations
  33. GRB000926 Host Galaxy Observations
  34. GRB 010222: HST observations -- host galaxy and late-time decay
  35. GRB 010222 - WHT BVRI images
  36. GRB 010629 Optical Observations
  37. GRB010629: Optical Observations
  38. SGR1900+14: High Fluence Burst Localized by HETE
  39. GRB010629, optical observations
  40. GRB010629: A Burst Localized by HETE
  41. SGR1900+14: Second Burst Localized by HETE
  42. SGR1900+14: A Burst Localized by HETE
  43. SGR1806-20: A Second, Intense Burst Localized by HETE
  44. GRB 00630: Host Galaxy
  45. SGR1806-20: Localization by HETE
  46. GRB000301C: Late-time HST/STIS observation
  47. GRB000418: HST/STIS Second-epoch Observations
  48. GRB010214, optical observations
  49. GRB010427, Gamma Ray Observations
  50. SGR 1900+14: No evidence of extended X-ray emission
  51. SGR 1900+14 : RXTE observations
  52. GRB 010222 /corrections to VBT data
  53. Millimeter observation of SGR 1900+14
  54. Chandra Observations of SGR 1900+14
  55. SGR 1900+14, Chandra observations
  56. Chandra Observations of SGR 1900+14
  57. SGR1900+14, I-band observations
  58. GRB 010326b Optical Observations
  59. GRB010412: Optical observations
  60. GRB010412: Optical observations
  61. GRB010412: BeppoSAX GRBM and WFC observations
  62. GRB Observation Report
  63. GRB 980326: Late-time HST/STIS observations
  64. Further Optical Observations of GRB 010324
  65. GRB010222, CXO X-ray observations
  66. GRB 010326A: Further optical observations
  67. GRB 010326B: Optical observations
  68. GRB010324, optical observations
  69. GRB010326B: Localization by HETE (2nd GRB for this date)
  70. GRB 010326: Optical observations
  71. GRB 010326 optical observations
  72. GRB010326: Refined Localization by HETE
  73. GRB010326: Localization by HETE
  74. Optical Observations of GRB 010324
  75. IPN TRIANGULATION OF GRB010324
  76. GRB990705, VLT-FORS1 observations of the host galaxy
  77. GRB 010222 - HEGRA GeV/TeV Observations
  78. GRB010222: Sub-millimeter vanishing act
  79. GRB 010222, Optical Observations
  80. Sub-millimeter Excess/GRB 010222
  81. GRB 010222
  82. GRB 010222 HST/Chandra TOO
  83. GRB010222 further R-band photometry
  84. GRB010222 Optical observations
  85. GRB010222, field photometry
  86. GRB010222 further R-band photometry
  87. GRB010222, possible increase of optical decay slope
  88. GRB 010222 BV optical observations
  89. GRB010220, Optical Observations
  90. GRB010222 R-BAND OBSERVATION
  91. GRB 010220: Near-IR Observations
  92. GRB010214 follow-up from Hanle
  93. GRB 010222: Near-IR Observations
  94. GRB 010222: Optical Observations
  95. GRB010222: Optical decay slope
  96. GRB 010214, Optical Observations
  97. GRB010222: Sub-millimeter detection
  98. GRB010222: R-band fading behavior
  99. GRB010222: Optical Observations
  100. GRB010222, radio observations

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