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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"

21796 results found.

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

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