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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"

37988 results found.

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

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