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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"

25717 results found.

  1. GRB011130 (XRF011130) SDSS PT i-band observations
  2. XRF011130: Infrared Observations
  3. GRB 011121
  4. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  5. GRB 011121: J-band observations
  6. GRB 011121: NIR observations, host galaxy?
  7. GRB011121: UBRI Observations
  8. GRB 011121 J-Band Astrometry
  9. GRB 011121: Detection of Bright IR Counterpart
  10. GRB011121: possible redshift, continued decay
  11. GRB 011030: TNG K-band observation
  12. XRF011030: J and K band observations
  13. XRF011030: Chandra Observations
  14. GRB011030: Z-band observations
  15. GRB 011030 R band observations
  16. GRB 011030 I-band Observation
  17. The X-ray Flash 011030 ('GRB 011030')
  18. Non-triggered burst 011030 ("GRB 011030")
  19. The Radio Afterglow from the X-ray Rich GRB 011030
  20. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  21. GRB 970828: HST Observations of the Host Galaxy
  22. GRB 000131: HST Detection of the Host Galaxy
  23. GRB 970828: HST Observations of the Host Galaxy
  24. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  25. GRB011019: Subaru Optical Observations
  26. GRB 011030 I-band Observations
  27. GRB 011030 K-band Observations
  28. GRB010921, optical observations
  29. GRB011030 - further refinement WFC position
  30. GRB 011030, Radio observations
  31. GRB011030: radio search
  32. GRB 010921: Possible supernova component
  33. GRB010921, optical observation at early time
  34. GRB 010921, I-band observations
  35. GRB011019, optical observations
  36. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  37. GRB 010921: The afterglow of HETE #1761
  38. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  39. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  40. GRB010923 as seen by BeppoSAX GRBM
  41. GRB010928(=H1770): Localization of a Long GRB by HETE
  42. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  43. GRB010921, negative optical observations
  44. GRB010921 field photometry
  45. H1761: A Bright GRB Detected by HETE
  46. GRB000926, Host Galaxy Observations
  47. GRB001109, Host Galaxy Spectroscopic Observations
  48. Probable SGR or Short Duration GRB Detected by HETE
  49. GCN and HETE status
  50. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  51. GRB 010222 - WHT BVRI images
  52. SGR1900+14 burst seen by HETE: BeppoSAX data
  53. GRB 010629 Optical Observations
  54. SGR1900+14: High Fluence Burst Localized by HETE
  55. GRB010629, optical observations
  56. GRB010629: A Burst Localized by HETE
  57. SGR1900+14: Second Burst Localized by HETE
  58. SGR1900+14: A Burst Localized by HETE
  59. SGR1806-20: A Second, Intense Burst Localized by HETE
  60. SGR1806-20: Localization by HETE
  61. HETE Fully-Automated GCN Notices
  62. GRB000301C: Late-time HST/STIS observation
  63. GRB010518: a faint BeppoSAX detection
  64. GRB000418: HST/STIS Second-epoch Observations
  65. X-ray precursors to the large flare from SGR 1900+14
  66. GRB010427, Gamma Ray Observations
  67. SGR 1900+14: No evidence of extended X-ray emission
  68. SGR 1900+14 : RXTE observations
  69. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  70. SGR 1900+14: Correction to GCN 1049
  71. GRB 010222 /corrections to VBT data
  72. Millimeter observation of SGR 1900+14
  73. SGR 1900+14: Detection of extended X-ray emission
  74. SGR 1900+14, Chandra observations
  75. SGR1900+14, I-band observations
  76. GRB010412, field photometry
  77. Giant flare from SGR1900+14
  78. GRB 010326b Optical Observations
  79. GRB010412: BeppoSAX GRBM and WFC observations
  80. GRB010324, revised field photometry
  81. REVISED LOCATION OF GRB010326A
  82. GRB 980326: Late-time HST/STIS observations
  83. GRB010324, field photometry
  84. GRB010326B, field photometry
  85. GRB010326, field photometry
  86. GRB010220, field photometry
  87. Further Optical Observations of GRB 010324
  88. GRB010222, CXO X-ray observations
  89. GRB010324, optical observations
  90. GRB010326B: Localization by HETE (2nd GRB for this date)
  91. GRB 010326 optical observations
  92. GRB010326: Refined Localization by HETE
  93. GRB010326: Localization by HETE
  94. Optical Observations of GRB 010324
  95. GRB010222, late-time optical observation
  96. Support extension to the BeppoSAX mission
  97. GRB 010222 - HEGRA GeV/TeV Observations
  98. GRB010222: Chandra X-ray Observatory Observation
  99. GRB010222: Sub-millimeter vanishing act
  100. GRB010222 - Optical observation

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