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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"

35987 results found.

  1. GRB 000301C: Optical Spectrum and Redshift
  2. GRB 000301C: A Precise Redshift Determination
  3. GRB 000301C, Optical Observation
  4. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  5. GRB 000301C: HST/STIS CCD Imaging of the field
  6. IPN error box for GRB000307
  7. GRB 000301c: K' observations
  8. GRB000301C, optical R-band observations
  9. GRB000301c - R photometry and nearby faint source confirmation
  10. GRB 000301C, Optical Observation
  11. GRB 000301c: K' observations
  12. GRB 000301C Optical Observations
  13. GRB 000301C: K' Observations
  14. GRB000301C - Host galaxy not detected in R (?)
  15. GRB000301C optical observations
  16. GRB 000301c near-IR observations
  17. GRB 000301C, Optical Color
  18. GRB000301C, Optical Spectroscopy
  19. GRB 000301C, UBVRI field photometry
  20. GRB 000301C, Optical Observation
  21. GRB000301C 250 GHz detection
  22. GRB 000301C R-band observation
  23. GRB 000301C, Optical Observation
  24. GRB000301C, near-infrared observations (JHK' photometry)
  25. GRB 000301C: OT confirmed
  26. GRB000301c optical observations
  27. GRB 000301A, Radio Observations
  28. GRB000301C, optical observations
  29. GRB000301c, near-infrared observations
  30. GRB000301C
  31. GRB 000301C : Optical Candidate
  32. GRB000301C: RXTE/ASM and IPN localizations
  33. GRB000226 [IPN Position]
  34. HST Observations of GRB 990712
  35. GRB 000214 near-IR observations
  36. GRB 000115 Optical observations
  37. GRB 000214, Radio Observations
  38. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  39. GRB 000115, BVRI field photometry
  40. IPN annulus for GRB000214
  41. BATSE GRB trigger criterion changed
  42. GRB000210 X-ray afterglow
  43. GRB000214: X-ray afterglow candidate
  44. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  45. GRB 000210: BATSE Observations
  46. Optical observations of the Chandra X-ray source for GRB000210
  47. Chandra Observations of GRB000210 X-ray Afterglow
  48. IPN triangulation of GRB000210
  49. GRB 000201: TAROT optical observations
  50. GRB 000131 Optical Observations
  51. GRB000126 Optical Observations
  52. BATSE GRB trigger criteria changed
  53. GRB 991208, radio observations
  54. BATSE+IPN location of GRB000131
  55. IPN localization of GRB000131
  56. GRB 000126, optical observations
  57. GRB000126, optical observations
  58. BATSE location of GRB000126
  59. IPN localization of GRB000126
  60. GRB 000115 Optical observations
  61. BATSE Observations of GRB000115
  62. Second RXTE Observation of GRB 000115
  63. GRB991216, UBVRIJHK field photometry
  64. Single IPN error box for GRB991229
  65. GRB 991216 VLBA Observations
  66. BEPPOSAX GRBM Localization of GRB991226
  67. IPN error boxes for GRB991229
  68. GRB 991216: J band spectrophotometry
  69. GRB 991216: Detection of the Host and/or Absorber Galaxy
  70. IPN localization of GRB991226
  71. Single IPN error box for GRB991221
  72. IPN error boxes for GRB991221
  73. GRB 991216 RXTE ASM Observations
  74. IPN error box for GRB991216
  75. GRB 991216: Updated BATSE parameters
  76. Lowell/Perkins observation of GRB 991216
  77. GRB 991217 (SAX J2303.2+0015) Optical observations
  78. Chandra observation of the X-ray afterglow of GRB991216
  79. GRB 991216, optical observations
  80. GRB 991216 Optical Observations
  81. GRB 991216 Optical spectroscopy/imaging
  82. K observations of GRB991216
  83. GRB 991217 (SAX J2303.2+0015) Optical observations
  84. GRB991216 Spectroscopy
  85. Lowell/Perkins observation of GRB 991216
  86. GRB991216, optical observations
  87. Refined IPN localization of GRB991216
  88. GRB 991216 Radio Observations
  89. GRB 991217
  90. GRB 991208 Keck Spectroscopy
  91. GRB 991208 Infrared Detection
  92. GRB 991216--Summary of RXTE Observations
  93. GRB 991216 Optical Observations
  94. GRB 991216, optical observations
  95. GRB 991208 SAO-RAS Spectroscopy
  96. SAX J2303.2+0015: an x-ray/GRB?
  97. GRB 991216, Optical Transient
  98. GRB 991216, Optical Afterglow
  99. GRB 991216: Comparison with DPOSS images
  100. GRB 991208 optical observations

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