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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"

36080 results found.

  1. GRB 000301C, Optical Observation
  2. GRB 000301c: K' observations
  3. GRB 000301C Optical Observations
  4. GRB 000301C: K' Observations
  5. GRB000301C - Host galaxy not detected in R (?)
  6. GRB000301C optical observations
  7. GRB 000301c near-IR observations
  8. GRB 000301C, Optical Color
  9. GRB000301C, Optical Spectroscopy
  10. GRB 000301C, UBVRI field photometry
  11. GRB 000301C, Optical Observation
  12. GRB000301C 250 GHz detection
  13. GRB 000301C R-band observation
  14. GRB 000301C, Optical Observation
  15. GRB000301C, near-infrared observations (JHK' photometry)
  16. GRB 000301C: OT confirmed
  17. GRB000301c optical observations
  18. GRB 000301A, Radio Observations
  19. GRB000301C, optical observations
  20. GRB000301c, near-infrared observations
  21. GRB000301C
  22. GRB 000301C : Optical Candidate
  23. GRB000301C: RXTE/ASM and IPN localizations
  24. GRB000226 [IPN Position]
  25. HST Observations of GRB 990712
  26. GRB 000214 near-IR observations
  27. GRB 000115 Optical observations
  28. GRB 000214, Radio Observations
  29. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  30. GRB 000115, BVRI field photometry
  31. IPN annulus for GRB000214
  32. BATSE GRB trigger criterion changed
  33. GRB000210 X-ray afterglow
  34. GRB000214: X-ray afterglow candidate
  35. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  36. GRB 000210: BATSE Observations
  37. Optical observations of the Chandra X-ray source for GRB000210
  38. Chandra Observations of GRB000210 X-ray Afterglow
  39. IPN triangulation of GRB000210
  40. GRB 000201: TAROT optical observations
  41. GRB 000131 Optical Observations
  42. GRB000126 Optical Observations
  43. BATSE GRB trigger criteria changed
  44. GRB 991208, radio observations
  45. BATSE+IPN location of GRB000131
  46. IPN localization of GRB000131
  47. GRB 000126, optical observations
  48. GRB000126, optical observations
  49. BATSE location of GRB000126
  50. IPN localization of GRB000126
  51. GRB 000115 Optical observations
  52. BATSE Observations of GRB000115
  53. Second RXTE Observation of GRB 000115
  54. GRB991216, UBVRIJHK field photometry
  55. Single IPN error box for GRB991229
  56. GRB 991216 VLBA Observations
  57. BEPPOSAX GRBM Localization of GRB991226
  58. IPN error boxes for GRB991229
  59. GRB 991216: J band spectrophotometry
  60. GRB 991216: Detection of the Host and/or Absorber Galaxy
  61. IPN localization of GRB991226
  62. Single IPN error box for GRB991221
  63. IPN error boxes for GRB991221
  64. GRB 991216 RXTE ASM Observations
  65. IPN error box for GRB991216
  66. GRB 991216: Updated BATSE parameters
  67. Lowell/Perkins observation of GRB 991216
  68. GRB 991217 (SAX J2303.2+0015) Optical observations
  69. Chandra observation of the X-ray afterglow of GRB991216
  70. GRB 991216, optical observations
  71. GRB 991216 Optical Observations
  72. GRB 991216 Optical spectroscopy/imaging
  73. VLT spectra of GRB991216
  74. K observations of GRB991216
  75. GRB 991217 (SAX J2303.2+0015) Optical observations
  76. GRB991216 Spectroscopy
  77. Lowell/Perkins observation of GRB 991216
  78. GRB991216, optical observations
  79. Refined IPN localization of GRB991216
  80. GRB 991216 Radio Observations
  81. GRB 991217
  82. GRB 991208 Keck Spectroscopy
  83. GRB 991208 Infrared Detection
  84. GRB 991216--Summary of RXTE Observations
  85. GRB 991216 Optical Observations
  86. GRB 991216, optical observations
  87. GRB 991208 SAO-RAS Spectroscopy
  88. SAX J2303.2+0015: an x-ray/GRB?
  89. GRB 991216, Optical Transient
  90. GRB 991216, Optical Afterglow
  91. GRB 991216: Comparison with DPOSS images
  92. GRB 991208 optical observations
  93. Lowell/Perkins observation of GRB 991216
  94. GRB 991216 Optical Observation
  95. GRB 991208 Keck Spectroscopy
  96. GRB 991216: Extremely bright BATSE burst
  97. GRB991208, optical observations
  98. GRB 991208 Keck Spectroscopy
  99. GRB991208 - millimeter detection
  100. GRB 991208, Optical Observation

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