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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"

15556 results found.

  1. GRB 000307, Optical Observations
  2. GRB 000307, BVRI Field Photometry
  3. GRB 000301C: Optical Spectrum and Redshift
  4. GRB 000301C: Optical Spectrum and Redshift
  5. GRB 000301C: A Precise Redshift Determination
  6. GRB 000301C, Optical Observation
  7. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  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 Optical Observations
  13. GRB 000301C: K' Observations
  14. GRB000301C OT candidate optical observations
  15. GRB000301C - Host galaxy not detected in R (?)
  16. Optical observations of GRB000301c
  17. GRB000301C, Radio observations
  18. GRB000301C, Radio observations
  19. GRB000301C optical observations
  20. GRB 000301c near-IR observations
  21. GRB 000301C, Optical Color
  22. GRB000301C, Optical Spectroscopy
  23. GRB 000301C, UBVRI field photometry
  24. GRB 000301C, Optical Observation
  25. GRB000301C, optical observations
  26. GRB 000301C R-band observation
  27. GRB 000301C, Optical Observation
  28. GRB000301C, near-infrared observations (JHK' photometry)
  29. GRB 000301C: OT confirmed
  30. GRB000301c optical observations
  31. GRB000301C, optical observations
  32. GRB000301c, near-infrared observations
  33. GRB 000301C : Optical Candidate
  34. GRB 000115 Optical observations
  35. GRB 000115, BVRI field photometry
  36. Optical observations of GRB000210
  37. GRB000210 X-ray afterglow
  38. Correction to Chandra Position of GRB000210 afterglow
  39. Optical observations of the Chandra X-ray source for GRB000210
  40. Optical candidate for GRB000210
  41. GRB000201, Radio Observations
  42. Optical observations of GRB000131
  43. GRB000201 Optical Observations
  44. GRB 000201: TAROT optical observations
  45. GRB 000131 Optical Observations
  46. GRB000126 Optical Observations
  47. GRB 000126, optical observations
  48. GRB000126, optical observations
  49. GRB 000115 Optical observations
  50. GRB991216 late optical observation
  51. GRB 991216 VLBA Observations
  52. GRB 991216: J band spectrophotometry
  53. GRB 991216 RXTE ASM Observations
  54. IPN error box for GRB991216
  55. GRB 991217 (SAX J2303.2+0015) Optical observations
  56. GRB991217/SAX J2303.2+0015, optical observations
  57. Chandra observation of the X-ray afterglow of GRB991216
  58. GRB 991216, optical observations
  59. GRB 991216 Optical Observations
  60. GRB 991216 Optical spectroscopy/imaging
  61. VLT spectra of GRB991216
  62. GRB991216 Optical and IR observations
  63. SAX J2303.2+0015 Optical observations
  64. IR observations of GRB991216
  65. GRB991216 radio observations
  66. GRB 991217 (SAX J2303.2+0015) Optical observations
  67. GRB991216 radio observations
  68. GRB991216, optical observations
  69. GRB991216 Optical and infrared observations of Beethoven Burst
  70. Refined IPN localization of GRB991216
  71. GRB 991216 Radio Observations
  72. GRB 991208 Infrared Detection
  73. GRB 991216--Summary of RXTE Observations
  74. GRB 991216 Optical Observations
  75. GRB 991216, optical observations
  76. GRB 991208 SAO-RAS Spectroscopy
  77. GRB 991216, Optical Transient
  78. GRB 991216, Optical Afterglow
  79. GRB991216 ('Beethoven Burst') B, R, and K Observations
  80. GRB991216 Optical Observations
  81. GRB 991208 optical observations
  82. Lowell/Perkins observation of GRB 991216
  83. GRB 991216 Optical Observation
  84. GRB 991208 Keck Spectroscopy
  85. R-band Observations of GRB991208 at TNG
  86. GRB991208, optical observations
  87. GRB 991208, Optical Observation
  88. GRB991208, optical observations
  89. GRB 991208 Optical Decay
  90. GRB 991208 optical observations
  91. GRB 991208 optical observations
  92. GRB 991208: Radio Observations
  93. Optical Observations of GRB991105
  94. GRB 991106, optical observations
  95. GRB 991106 Optical Observations
  96. GRB 991105, optical observations
  97. GRB991106, optical observation at SAO-RAS
  98. GRB 991106, LOTIS Optical Observations
  99. GRB 991106, optical observations
  100. GRB 991014, Optical Observations

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