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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"

21793 results found.

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

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