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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"

33671 results found.

  1. GRB 000301C, UBVRI field photometry
  2. GRB 000301C, Optical Observation
  3. GRB000301C 250 GHz detection
  4. GRB 000301C R-band observation
  5. GRB 000301C, Optical Observation
  6. GRB000301C, near-infrared observations (JHK' photometry)
  7. GRB 000301C: OT confirmed
  8. GRB000301c optical observations
  9. GRB 000301A, Radio Observations
  10. GRB000301C, optical observations
  11. GRB000301c, near-infrared observations
  12. GRB000301C
  13. GRB 000301C : Optical Candidate
  14. GRB000301C: RXTE/ASM and IPN localizations
  15. GRB000226 [IPN Position]
  16. HST Observations of GRB 990712
  17. GRB 000214 near-IR observations
  18. GRB 000115 Optical observations
  19. GRB 000214, Radio Observations
  20. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  21. GRB 000115, BVRI field photometry
  22. IPN annulus for GRB000214
  23. BATSE GRB trigger criterion changed
  24. GRB000210 X-ray afterglow
  25. GRB000214: X-ray afterglow candidate
  26. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  27. GRB 000210: BATSE Observations
  28. Optical observations of the Chandra X-ray source for GRB000210
  29. Chandra Observations of GRB000210 X-ray Afterglow
  30. IPN triangulation of GRB000210
  31. GRB 000201: TAROT optical observations
  32. GRB 000131 Optical Observations
  33. GRB000126 Optical Observations
  34. BATSE GRB trigger criteria changed
  35. GRB 991208, radio observations
  36. BATSE+IPN location of GRB000131
  37. IPN localization of GRB000131
  38. GRB 000126, optical observations
  39. GRB000126, optical observations
  40. BATSE location of GRB000126
  41. IPN localization of GRB000126
  42. GRB 000115 Optical observations
  43. BATSE Observations of GRB000115
  44. Second RXTE Observation of GRB 000115
  45. GRB991216, UBVRIJHK field photometry
  46. Single IPN error box for GRB991229
  47. GRB 991216 VLBA Observations
  48. BEPPOSAX GRBM Localization of GRB991226
  49. IPN error boxes for GRB991229
  50. GRB 991216: J band spectrophotometry
  51. GRB 991216: Detection of the Host and/or Absorber Galaxy
  52. IPN localization of GRB991226
  53. Single IPN error box for GRB991221
  54. IPN error boxes for GRB991221
  55. GRB 991216 RXTE ASM Observations
  56. IPN error box for GRB991216
  57. GRB 991216: Updated BATSE parameters
  58. Lowell/Perkins observation of GRB 991216
  59. GRB 991217 (SAX J2303.2+0015) Optical observations
  60. Chandra observation of the X-ray afterglow of GRB991216
  61. GRB 991216, optical observations
  62. GRB 991216 Optical Observations
  63. GRB 991216 Optical spectroscopy/imaging
  64. VLT spectra of GRB991216
  65. K observations of GRB991216
  66. GRB 991217 (SAX J2303.2+0015) Optical observations
  67. GRB991216 Spectroscopy
  68. Lowell/Perkins observation of GRB 991216
  69. GRB991216, optical observations
  70. Refined IPN localization of GRB991216
  71. GRB 991216 Radio Observations
  72. GRB 991217
  73. GRB 991208 Keck Spectroscopy
  74. GRB 991208 Infrared Detection
  75. GRB 991216--Summary of RXTE Observations
  76. GRB 991216 Optical Observations
  77. GRB 991216, optical observations
  78. GRB 991208 SAO-RAS Spectroscopy
  79. SAX J2303.2+0015: an x-ray/GRB?
  80. GRB 991216, Optical Transient
  81. GRB 991216, Optical Afterglow
  82. GRB 991216: Comparison with DPOSS images
  83. GRB 991208 optical observations
  84. Lowell/Perkins observation of GRB 991216
  85. GRB 991216 Optical Observation
  86. GRB 991208 Keck Spectroscopy
  87. GRB 991216: Extremely bright BATSE burst
  88. GRB991208, optical observations
  89. GRB 991208 Keck Spectroscopy
  90. GRB991208 - millimeter detection
  91. GRB 991208, Optical Observation
  92. GRB 991208 - OVRO detection
  93. GRB 991208 Optical Decay
  94. GRB 991208 optical observations
  95. GRB 991208 optical observations
  96. GRB 991208: Radio Observations
  97. IPN localization of GRB991208
  98. Optical Observations of GRB991105
  99. GRB991106: BeppoSAX/BATSE results
  100. GRB 991106, optical observations

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