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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"

15985 results found.

  1. GRB000424, optical observations
  2. GRB 000429, optical observation
  3. GRB 000429, UBVRI field photometry
  4. GRB000418, Radio detection
  5. GRB 000418, Optical Observation
  6. GRB 000418, optical observation
  7. GRB000424 Optical Observations
  8. GRB 000418, Optical Observation
  9. GRB000424, optical observations
  10. GRB000424, optical observations
  11. GRB 000424, Optical Observations
  12. GRB 000418, Optical Observation
  13. GRB000416 Optical Observations
  14. GRB000416 BRJK observations
  15. GRB 000408, optical observations
  16. GRB 991208, UBVRI field photometry
  17. GRB000301c results
  18. GRB000408: Optical CCD Observations from MIRO
  19. GRB000408, lotis optical observations
  20. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  21. GRB000326 Optical Observations
  22. GRB000301C - R magnitude lower limit
  23. GRB 000323, optical observations
  24. GRB 000326: Optical Observations
  25. GRB 000307 optical observations
  26. GRB000313, Radio observations
  27. GRB 000313 - optical transient in the BATSE error box
  28. GRB000301C - B and R photometry
  29. GRB000301C - R photometry
  30. GRB 000307, Optical Observations
  31. GRB 000307, BVRI Field Photometry
  32. GRB 000301C: Optical Spectrum and Redshift
  33. GRB 000301C: Optical Spectrum and Redshift
  34. GRB 000301C: A Precise Redshift Determination
  35. GRB 000301C, Optical Observation
  36. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  37. GRB 000301c: K' observations
  38. GRB000301C, optical R-band observations
  39. GRB000301c - R photometry and nearby faint source confirmation
  40. GRB 000301C, Optical Observation
  41. GRB 000301C Optical Observations
  42. GRB 000301C: K' Observations
  43. GRB000301C OT candidate optical observations
  44. GRB000301C - Host galaxy not detected in R (?)
  45. Optical observations of GRB000301c
  46. GRB000301C, Radio observations
  47. GRB000301C, Radio observations
  48. GRB000301C optical observations
  49. GRB 000301c near-IR observations
  50. GRB 000301C, Optical Color
  51. GRB000301C, Optical Spectroscopy
  52. GRB 000301C, UBVRI field photometry
  53. GRB 000301C, Optical Observation
  54. GRB000301C, optical observations
  55. GRB 000301C R-band observation
  56. GRB 000301C, Optical Observation
  57. GRB000301C, near-infrared observations (JHK' photometry)
  58. GRB 000301C: OT confirmed
  59. GRB000301c optical observations
  60. GRB000301C, optical observations
  61. GRB000301c, near-infrared observations
  62. GRB 000301C : Optical Candidate
  63. GRB 000115 Optical observations
  64. GRB 000115, BVRI field photometry
  65. Optical observations of GRB000210
  66. GRB000210 X-ray afterglow
  67. Correction to Chandra Position of GRB000210 afterglow
  68. Optical observations of the Chandra X-ray source for GRB000210
  69. Optical candidate for GRB000210
  70. GRB000201, Radio Observations
  71. Optical observations of GRB000131
  72. GRB000201 Optical Observations
  73. GRB 000201: TAROT optical observations
  74. GRB 000131 Optical Observations
  75. GRB000126 Optical Observations
  76. GRB 000126, optical observations
  77. GRB000126, optical observations
  78. GRB 000115 Optical observations
  79. GRB991216 late optical observation
  80. GRB 991216 VLBA Observations
  81. GRB 991216: J band spectrophotometry
  82. GRB 991216 RXTE ASM Observations
  83. IPN error box for GRB991216
  84. GRB 991217 (SAX J2303.2+0015) Optical observations
  85. GRB991217/SAX J2303.2+0015, optical observations
  86. Chandra observation of the X-ray afterglow of GRB991216
  87. GRB 991216, optical observations
  88. GRB 991216 Optical Observations
  89. GRB 991216 Optical spectroscopy/imaging
  90. VLT spectra of GRB991216
  91. GRB991216 Optical and IR observations
  92. SAX J2303.2+0015 Optical observations
  93. IR observations of GRB991216
  94. GRB991216 radio observations
  95. GRB 991217 (SAX J2303.2+0015) Optical observations
  96. GRB991216 radio observations
  97. GRB991216, optical observations
  98. GRB991216 Optical and infrared observations of Beethoven Burst
  99. Refined IPN localization of GRB991216
  100. GRB 991216 Radio Observations

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