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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"

32500 results found.

  1. GRB000210 X-ray afterglow
  2. GRB 000210: BATSE Observations
  3. Correction to Chandra Position of GRB000210 afterglow
  4. Optical observations of the Chandra X-ray source for GRB000210
  5. GRB000210, Radio Observations
  6. Optical candidate for GRB000210
  7. Chandra Observations of GRB000210 X-ray Afterglow
  8. IPN triangulation of GRB000210
  9. GRB000201, Radio Observations
  10. Optical observations of GRB000131
  11. GRB000201 Optical Observations
  12. GRB 000131 Optical Observations
  13. GRB000126 Optical Observations
  14. GRB 991208, radio observations
  15. BATSE+IPN location of GRB000131
  16. GRB 000126, optical observations
  17. GRB000126, optical observations
  18. BATSE location of GRB000126
  19. GRB 000115 Optical observations
  20. BATSE Observations of GRB000115
  21. Correction to GCN 520 (IPN annulus for GRB000115)
  22. IPN annulus for GRB000115
  23. GRB991216, UBVRIJHK field photometry
  24. GRB991216 late optical observation
  25. Single IPN error box for GRB991229
  26. GCN resumes full operations
  27. GRB 991216 VLBA Observations
  28. BEPPOSAX GRBM Localization of GRB991226
  29. GRB 991216: J band spectrophotometry
  30. GRB 991216: Detection of the Host and/or Absorber Galaxy
  31. Single IPN error box for GRB991221
  32. GRB 991216 RXTE ASM Observations
  33. IPN error box for GRB991216
  34. Lowell/Perkins observation of GRB 991216
  35. GRB 991217 (SAX J2303.2+0015) Optical observations
  36. GRB991217/SAX J2303.2+0015, optical observations
  37. Chandra observation of the X-ray afterglow of GRB991216
  38. GRB 991216, optical observations
  39. GRB 991216 Optical Observations
  40. GRB 991216 Optical spectroscopy/imaging
  41. VLT spectra of GRB991216
  42. GRB991216 Optical and IR observations
  43. SAX J2303.2+0015 Optical observations
  44. IR observations of GRB991216
  45. GRB991216 radio observations
  46. GRB 991217 (SAX J2303.2+0015) Optical observations
  47. GRB991216 radio observations
  48. Lowell/Perkins observation of GRB 991216
  49. GRB991216, optical observations
  50. Refined IPN localization of GRB991216
  51. GRB 991216 Radio Observations
  52. GRB 991208 Keck Spectroscopy
  53. GRB 991208 Infrared Detection
  54. GRB991216
  55. GRB 991216--Summary of RXTE Observations
  56. GRB 991216 Optical Observations
  57. GRB 991216, optical observations
  58. GRB 991208 SAO-RAS Spectroscopy
  59. GRB 991216, Optical Transient
  60. GRB 991216, Optical Afterglow
  61. GRB991216 ('Beethoven Burst') B, R, and K Observations
  62. GRB 991216: Comparison with DPOSS images
  63. GRB 991208 optical observations
  64. Lowell/Perkins observation of GRB 991216
  65. GRB 991216 Optical Observation
  66. GRB 991208 Keck Spectroscopy
  67. R-band Observations of GRB991208 at TNG
  68. GRB991208, optical observations
  69. GRB 991208 Keck Spectroscopy
  70. GRB991208 - millimeter detection
  71. GRB 991208, Optical Observation
  72. GRB991208 15-GHz observations
  73. GRB991208, optical observations
  74. GRB 991208 - OVRO detection
  75. GRB 991208 Optical Decay
  76. GRB 991208 optical observations
  77. GRB 991208 optical observations
  78. GRB 991208: Radio Observations
  79. Optical Observations of GRB991105
  80. GRB991106: BeppoSAX/BATSE results
  81. GRB 991106, optical observations
  82. GRB991106, near-infrared observations
  83. BeppoSAX NFI Observation of GRB991106
  84. GRB 991106, radio observations
  85. GRB 991105: BATSE Observations
  86. IPN localization of GRB991105
  87. GRB 991106 Optical Observations
  88. GRB 991105, optical observations
  89. GRB991106, optical observation at SAO-RAS
  90. GRB 991106, LOTIS Optical Observations
  91. GRB 991106, optical observations
  92. Revised BeppoSAX WFC position of GRB991105
  93. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  94. GRB 991014, Optical Observations
  95. GRB 991014 - BeppoSAX NFI observations
  96. GRB 991014, Optical Observations
  97. GRB 991014, Optical Observations
  98. GRB 991014, optical observations
  99. Super-LOTIS optical observation of GRB991014
  100. IPN/NFI error box for GRB991014

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