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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"

27321 results found.

  1. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  2. GRB 011130, K band observations
  3. GRB011130, optical observations
  4. GRB011130 (=XRF011130): Second Revised Localization by HETE
  5. GRB011130 (XRF011130) SDSS PT i-band observations
  6. XRF011130: Infrared Observations
  7. GRB 011121
  8. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  9. GRB 011121: J-band observations
  10. GRB 011121: NIR observations, host galaxy?
  11. GRB011121: UBRI Observations
  12. GRB 011121 J-Band Astrometry
  13. GRB 011121: Detection of Bright IR Counterpart
  14. GRB011121: possible redshift, continued decay
  15. GRB 011030: TNG K-band observation
  16. XRF011030: J and K band observations
  17. XRF011030: Chandra Observations
  18. GRB011030: Z-band observations
  19. GRB 011030 R band observations
  20. GRB 011030 I-band Observation
  21. The X-ray Flash 011030 ('GRB 011030')
  22. Non-triggered burst 011030 ("GRB 011030")
  23. The Radio Afterglow from the X-ray Rich GRB 011030
  24. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  25. GRB 970828: HST Observations of the Host Galaxy
  26. GRB 000131: HST Detection of the Host Galaxy
  27. GRB 970828: HST Observations of the Host Galaxy
  28. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  29. GRB011019: Subaru Optical Observations
  30. GRB 011030 I-band Observations
  31. GRB 011030 K-band Observations
  32. GRB010921, optical observations
  33. GRB011030 - further refinement WFC position
  34. GRB 011030, Radio observations
  35. GRB011030: radio search
  36. GRB 010921: Possible supernova component
  37. GRB010921, optical observation at early time
  38. GRB 010921, I-band observations
  39. GRB011019, optical observations
  40. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  41. GRB 010921: The afterglow of HETE #1761
  42. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  43. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  44. GRB010923 as seen by BeppoSAX GRBM
  45. GRB010928(=H1770): Localization of a Long GRB by HETE
  46. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  47. GRB010921, negative optical observations
  48. GRB010921 field photometry
  49. H1761: A Bright GRB Detected by HETE
  50. GRB000926, Host Galaxy Observations
  51. GRB001109, Host Galaxy Spectroscopic Observations
  52. Probable SGR or Short Duration GRB Detected by HETE
  53. GCN and HETE status
  54. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  55. GRB 010222 - WHT BVRI images
  56. SGR1900+14 burst seen by HETE: BeppoSAX data
  57. GRB 010629 Optical Observations
  58. SGR1900+14: High Fluence Burst Localized by HETE
  59. GRB010629, optical observations
  60. GRB010629: A Burst Localized by HETE
  61. SGR1900+14: Second Burst Localized by HETE
  62. SGR1900+14: A Burst Localized by HETE
  63. SGR1806-20: A Second, Intense Burst Localized by HETE
  64. SGR1806-20: Localization by HETE
  65. HETE Fully-Automated GCN Notices
  66. GRB000301C: Late-time HST/STIS observation
  67. GRB010518: a faint BeppoSAX detection
  68. GRB000418: HST/STIS Second-epoch Observations
  69. X-ray precursors to the large flare from SGR 1900+14
  70. GRB010427, Gamma Ray Observations
  71. SGR 1900+14: No evidence of extended X-ray emission
  72. SGR 1900+14 : RXTE observations
  73. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  74. SGR 1900+14: Correction to GCN 1049
  75. GRB 010222 /corrections to VBT data
  76. Millimeter observation of SGR 1900+14
  77. SGR 1900+14: Detection of extended X-ray emission
  78. SGR 1900+14, Chandra observations
  79. SGR1900+14, I-band observations
  80. GRB010412, field photometry
  81. Giant flare from SGR1900+14
  82. GRB 010326b Optical Observations
  83. GRB010412: BeppoSAX GRBM and WFC observations
  84. GRB010324, revised field photometry
  85. REVISED LOCATION OF GRB010326A
  86. GRB 980326: Late-time HST/STIS observations
  87. GRB010324, field photometry
  88. GRB010326B, field photometry
  89. GRB010326, field photometry
  90. GRB010220, field photometry
  91. Further Optical Observations of GRB 010324
  92. GRB010222, CXO X-ray observations
  93. GRB010324, optical observations
  94. GRB010326B: Localization by HETE (2nd GRB for this date)
  95. GRB 010326 optical observations
  96. GRB010326: Refined Localization by HETE
  97. GRB010326: Localization by HETE
  98. Optical Observations of GRB 010324
  99. GRB010222, late-time optical observation
  100. Support extension to the BeppoSAX mission

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