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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"

17643 results found.

  1. GRB000301C, Radio observations
  2. GRB 000301c near-IR observations
  3. GRB 000301C, UBVRI field photometry
  4. GRB000301C, near-infrared observations (JHK' photometry)
  5. GRB 000301C: OT confirmed
  6. GRB000301c optical observations
  7. GRB000301C
  8. GRB 000301C : Optical Candidate
  9. HST Observations of GRB 990712
  10. GRB 000214 near-IR observations
  11. GRB 000214, Radio Observations
  12. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  13. GRB000210, Radio Observations
  14. GRB 000115, BVRI field photometry
  15. GRB000214: BeppoSAX GRBM and WFC Detection
  16. Optical observations of GRB000210
  17. GRB000210 X-ray afterglow
  18. GRB000214: X-ray afterglow candidate
  19. GRB000214 refined BeppoSAX-WFC position
  20. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  21. Correction to Chandra Position of GRB000210 afterglow
  22. Optical observations of the Chandra X-ray source for GRB000210
  23. GRB000210, Radio Observations
  24. GRB000210: possible afterglow detection with BeppoSAX NFI
  25. GRB000201, Radio Observations
  26. GRB000210: BeppoSAX GRBM and WFC Detection
  27. GRB000201 Optical Observations
  28. GRB 000126, optical observations
  29. IPN localization of GRB000126
  30. IPN annulus for GRB000115
  31. GRB991216, UBVRIJHK field photometry
  32. GCN resumes full operations
  33. GRB 991216: Detection of the Host and/or Absorber Galaxy
  34. GRB 991216 RXTE ASM Observations
  35. GRB 991217 (SAX J2303.2+0015) Optical observations
  36. Chandra observation of the X-ray afterglow of GRB991216
  37. SAX J2303.2+0015 Optical observations
  38. IR observations of GRB991216
  39. GRB 991217 (SAX J2303.2+0015) Optical observations
  40. GRB 991216 Radio Observations
  41. GRB 991208 Infrared Detection
  42. GRB991216
  43. GRB 991216--Summary of RXTE Observations
  44. GRB 991216 Optical Observations
  45. GRB 991216, optical observations
  46. GRB 991208 SAO-RAS Spectroscopy
  47. SAX J2303.2+0015: an x-ray/GRB?
  48. GRB 991216, Optical Transient
  49. GRB991216 ('Beethoven Burst') B, R, and K Observations
  50. GRB991216, infrared observations
  51. GRB 991208 optical observations
  52. GRB 991216 Optical Observation
  53. GRB 991216: Extremely bright BATSE burst
  54. R-band Observations of GRB991208 at TNG
  55. GRB991208, optical observations
  56. GRB 991208, Optical Observation
  57. GRB991208, optical observations
  58. IPN localization of GRB991208
  59. Optical Observations of GRB991105
  60. GRB991106: BeppoSAX/BATSE results
  61. BeppoSAX NFI Observation of GRB991106
  62. GRB 991106, radio observations
  63. GRB991106: the first BeppoSAX short GRB detection?
  64. GRB 991106 Optical Observations
  65. GRB991106, optical observation at SAO-RAS
  66. GRB 991106, LOTIS Optical Observations
  67. GRB991105: SAX-GRBM/-WFC detection
  68. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  69. GRB 991014, Optical Observations
  70. GRB 991014 - BeppoSAX NFI observations
  71. GRB 991014, radio observations
  72. GRB 991014, Optical Observations
  73. GRB 991014, optical observations
  74. Optical Observations of GRB990907
  75. GRB990907: BeppoSAX follow up and X-ray afterglow
  76. GRB990907 and 990908
  77. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  78. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  79. GRB990806 BeppoSAX follow up
  80. GRB 990806 Optical observations
  81. GRB 990806, optical observations
  82. GRB 990806, Optical Observations
  83. GRB990806: possible X-ray afterglow, BeppoSAX
  84. GRB 990712 Optical Observations
  85. GRB 990712
  86. Late-time HST/STIS Observations of GRB 990510
  87. BeppoSAX NFI Observation of GRB990705
  88. BeppoSAX NFI Observation of GRB990705
  89. GRB 990705, R-band observations
  90. GRB990704: SAX-NFI results summary
  91. GRB990704 radio and optical observations
  92. GRB990704
  93. GRB990704, optical observations
  94. GRB990704: possible X-ray afterglow
  95. GRB990704
  96. GRB990704: BeppoSAX detection
  97. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  98. GRB 990627, radio observations
  99. Late-time HST/STIS Observation of GRB 990123
  100. Optical Observations of GRB 990506

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