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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"

16155 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: K' observations
  6. GRB000301C, optical R-band observations
  7. GRB000301c - R photometry and nearby faint source confirmation
  8. GRB 000301C, Optical Observation
  9. GRB 000301C Optical Observations
  10. GRB 000301C: K' Observations
  11. GRB000301C OT candidate optical observations
  12. GRB000301C - Host galaxy not detected in R (?)
  13. Optical observations of GRB000301c
  14. GRB000301C, Radio observations
  15. GRB000301C, Radio observations
  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, optical observations
  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. GRB000301C, optical observations
  29. GRB000301c, near-infrared observations
  30. GRB 000301C : Optical Candidate
  31. GRB 000115 Optical observations
  32. GRB 000115, BVRI field photometry
  33. Optical observations of GRB000210
  34. GRB000210 X-ray afterglow
  35. Correction to Chandra Position of GRB000210 afterglow
  36. Optical observations of the Chandra X-ray source for GRB000210
  37. Optical candidate for GRB000210
  38. GRB000201, Radio Observations
  39. Optical observations of GRB000131
  40. GRB000201 Optical Observations
  41. GRB 000201: TAROT optical observations
  42. GRB 000131 Optical Observations
  43. GRB000126 Optical Observations
  44. GRB 000126, optical observations
  45. GRB000126, optical observations
  46. GRB 000115 Optical observations
  47. GRB991216 late optical observation
  48. GRB 991216 VLBA Observations
  49. GRB 991216: J band spectrophotometry
  50. GRB 991216 RXTE ASM Observations
  51. IPN error box for GRB991216
  52. GRB 991217 (SAX J2303.2+0015) Optical observations
  53. GRB991217/SAX J2303.2+0015, optical observations
  54. Chandra observation of the X-ray afterglow of GRB991216
  55. GRB 991216, optical observations
  56. GRB 991216 Optical Observations
  57. GRB 991216 Optical spectroscopy/imaging
  58. VLT spectra of GRB991216
  59. GRB991216 Optical and IR observations
  60. SAX J2303.2+0015 Optical observations
  61. IR observations of GRB991216
  62. GRB991216 radio observations
  63. GRB 991217 (SAX J2303.2+0015) Optical observations
  64. GRB991216 radio observations
  65. GRB991216, optical observations
  66. GRB991216 Optical and infrared observations of Beethoven Burst
  67. Refined IPN localization of GRB991216
  68. GRB 991216 Radio Observations
  69. GRB 991208 Infrared Detection
  70. GRB 991216--Summary of RXTE Observations
  71. GRB 991216 Optical Observations
  72. GRB 991216, optical observations
  73. GRB 991208 SAO-RAS Spectroscopy
  74. GRB 991216, Optical Transient
  75. GRB 991216, Optical Afterglow
  76. GRB991216 ('Beethoven Burst') B, R, and K Observations
  77. GRB991216 Optical Observations
  78. GRB 991208 optical observations
  79. Lowell/Perkins observation of GRB 991216
  80. GRB 991216 Optical Observation
  81. GRB 991208 Keck Spectroscopy
  82. R-band Observations of GRB991208 at TNG
  83. GRB991208, optical observations
  84. GRB 991208, Optical Observation
  85. GRB991208, optical observations
  86. GRB 991208 Optical Decay
  87. GRB 991208 optical observations
  88. GRB 991208 optical observations
  89. GRB 991208: Radio Observations
  90. Optical Observations of GRB991105
  91. GRB 991106, optical observations
  92. GRB 991106 Optical Observations
  93. GRB 991105, optical observations
  94. GRB991106, optical observation at SAO-RAS
  95. GRB 991106, LOTIS Optical Observations
  96. GRB 991106, optical observations
  97. GRB 991014, Optical Observations
  98. GRB 991014, Optical Observations
  99. GRB 991014, Optical Observations
  100. GRB 991014, optical observations

Advanced

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