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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"
  1. GRB000301C, Radio observations
  2. GRB000301C, Radio observations
  3. GRB000301C optical observations
  4. GRB000301C, near-infrared observations (JHK' imaging)
  5. GRB 000301c near-IR observations
  6. GRB 000301C, Optical Color
  7. GRB000301C, Optical Spectroscopy
  8. GRB 000301C, UBVRI field photometry
  9. GRB 000301C, Optical Observation
  10. GRB000301C, optical observations
  11. GRB000301C 250 GHz detection
  12. GRB 000301C R-band observation
  13. GRB 000301C, Optical Observation
  14. GRB000301C, near-infrared observations (JHK' photometry)
  15. GRB 000301C: OT confirmed
  16. GRB000301c optical observations
  17. GRB 000301A, Radio Observations
  18. GRB000301C, optical observations
  19. GRB000301c, near-infrared observations
  20. GRB000301C
  21. GRB 000301C : Optical Candidate
  22. Radio observations of the error box of GRB000301A
  23. GRB000301C: RXTE/ASM and IPN localizations
  24. GRB000301A [IPN Position]
  25. GRB000226 [IPN Position]
  26. HST Observations of GRB 990712
  27. GRB 000214 near-IR observations
  28. GRB 000115 Optical observations
  29. GRB 000214, Radio Observations
  30. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  31. GRB000210, Radio Observations
  32. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  33. GRB 000115, BVRI field photometry
  34. GRB000214: BeppoSAX GRBM and WFC Detection
  35. IPN annulus for GRB000214
  36. BATSE GRB trigger criterion changed
  37. Optical observations of GRB000210
  38. GRB000210 X-ray afterglow
  39. GRB000214: X-ray afterglow candidate
  40. GRB000214 refined BeppoSAX-WFC position
  41. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  42. GRB 000210: BATSE Observations
  43. Correction to Chandra Position of GRB000210 afterglow
  44. Optical observations of the Chandra X-ray source for GRB000210
  45. GRB000210, Radio Observations
  46. Optical candidate for GRB000210
  47. Chandra Observations of GRB000210 X-ray Afterglow
  48. IPN triangulation of GRB000210
  49. GRB000210: possible afterglow detection with BeppoSAX NFI
  50. GRB000201, Radio Observations
  51. GRB000210: BeppoSAX GRBM and WFC Detection
  52. SAX_WFC_GRB_NOTICE
  53. SAX_WFC_GRB_NOTICE
  54. Optical observations of GRB000131
  55. GRB000201 Optical Observations
  56. GRB 000201: TAROT optical observations
  57. GRB 000131 Optical Observations
  58. GRB000126 Optical Observations
  59. BATSE GRB trigger criteria changed
  60. GRB 991208, radio observations
  61. BATSE+IPN location of GRB000131
  62. IPN localization of GRB000131
  63. GRB 000126, optical observations
  64. GRB000126, optical observations
  65. BATSE location of GRB000126
  66. IPN localization of GRB000126
  67. GRB 000115 Optical observations
  68. BATSE Observations of GRB000115
  69. Correction to GCN 520 (IPN annulus for GRB000115)
  70. IPN annulus for GRB000115
  71. Second RXTE Observation of GRB 000115
  72. GRB991216, UBVRIJHK field photometry
  73. GRB991216 late optical observation
  74. Single IPN error box for GRB991229
  75. GCN resumes full operations
  76. GRB 991216 VLBA Observations
  77. BEPPOSAX GRBM Localization of GRB991226
  78. IPN error boxes for GRB991229
  79. GRB 991216: J band spectrophotometry
  80. GRB 991216: Detection of the Host and/or Absorber Galaxy
  81. IPN localization of GRB991226
  82. Single IPN error box for GRB991221
  83. IPN error boxes for GRB991221
  84. GRB 991216 RXTE ASM Observations
  85. IPN error box for GRB991216
  86. GRB 991216: Updated BATSE parameters
  87. Lowell/Perkins observation of GRB 991216
  88. GRB 991217 (SAX J2303.2+0015) Optical observations
  89. GRB991217/SAX J2303.2+0015, optical observations
  90. Chandra observation of the X-ray afterglow of GRB991216
  91. GRB 991216, optical observations
  92. GRB 991216 Optical Observations
  93. GRB 991216 Optical spectroscopy/imaging
  94. VLT spectra of GRB991216
  95. GRB991216 Optical and IR observations
  96. K observations of GRB991216
  97. SAX J2303.2+0015 Optical observations
  98. IR observations of GRB991216
  99. GRB991216 radio observations
  100. GRB 991217 (SAX J2303.2+0015) Optical observations

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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