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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"

32494 results found.

  1. GRB000528, optical observations at ESO
  2. GRB 000604 optical observations
  3. GRB 000418: Detection of the Host Galaxy
  4. GRB000604, optical observations, comparison with DPOSS
  5. GRB000528, Radio Observations
  6. X-ray Afterglow of GRB 000529
  7. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  8. IPN localization and time history of GRB000528
  9. New IPN localization of GRB000529
  10. GRB000519: Optical observations
  11. IPN localization of GRB000529
  12. GRB 000528 - WFC measurements
  13. IPN triangulation of GRB000519
  14. Re: GRB000508B : Optical observations
  15. GRB 000418, Optical observation
  16. GRB000508B, optical photometry
  17. Possible GRB-related phenomenon
  18. GRB 000424 Optical Observations
  19. The redshift of GRB 000418
  20. GRB000424, optical observations
  21. GRB 000429, optical observation
  22. GRB000418, Radio detection
  23. GRB000418, K'-band photometry
  24. GRB 000418, Optical Observation
  25. GRB 000418, optical observation
  26. GRB000424 Optical Observations
  27. GRB 000418, Optical Observation
  28. GRB000424, optical observations
  29. GRB000424, optical observations
  30. GRB 000424, Optical Observations
  31. GRB 000418, Optical Observation
  32. GRB000418, near-infrared observations
  33. BeppoSAX GRB000424
  34. Correction to IPN error box for GRB000419
  35. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  36. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  37. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  38. GRB 000408, optical observations
  39. Refined IPN error box for GRB000408
  40. GRB000301c results
  41. GRB000408: Optical CCD Observations from MIRO
  42. GRB000408, lotis optical observations
  43. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  44. GRB000326 Optical Observations
  45. GRB000301C - Addendum to GCN 623
  46. GRB000326, Further VLA observations
  47. GRB 000323, optical observations
  48. GRB 000326: Optical Observations
  49. GRB000326, Radio observations
  50. GRB 000307 optical observations
  51. Single error box for GRB000315
  52. GRB000313, Radio observations
  53. GRB000301C - B and R photometry
  54. GRB 000307, Optical Observations
  55. GRB 000301C: Optical Spectrum and Redshift
  56. GRB 000301C: Optical Spectrum and Redshift
  57. GRB 000301C: A Precise Redshift Determination
  58. GRB 000301C, Optical Observation
  59. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  60. GRB 000301C: HST/STIS CCD Imaging of the field
  61. GRB000301C, optical R-band observations
  62. GRB000301c - R photometry and nearby faint source confirmation
  63. GRB 000301C, Optical Observation
  64. GRB 000301C Optical Observations
  65. GRB 000301C: K' Observations
  66. GRB000301C OT candidate optical observations
  67. Optical observations of GRB000301c
  68. GRB000301C, Radio observations
  69. GRB000301C, Radio observations
  70. GRB000301C, near-infrared observations (JHK' imaging)
  71. GRB 000301C, Optical Color
  72. GRB 000301C, UBVRI field photometry
  73. GRB 000301C, Optical Observation
  74. GRB000301C, optical observations
  75. GRB000301C 250 GHz detection
  76. GRB 000301C R-band observation
  77. GRB 000301C, Optical Observation
  78. GRB000301C, near-infrared observations (JHK' photometry)
  79. GRB 000301C: OT confirmed
  80. GRB000301c optical observations
  81. GRB 000301A, Radio Observations
  82. GRB000301C, optical observations
  83. GRB000301c, near-infrared observations
  84. GRB000301C
  85. GRB 000301C : Optical Candidate
  86. Radio observations of the error box of GRB000301A
  87. HST Observations of GRB 990712
  88. GRB 000115 Optical observations
  89. GRB 000214, Radio Observations
  90. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  91. GRB000210, Radio Observations
  92. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  93. IPN annulus for GRB000214
  94. Optical observations of GRB000210
  95. GRB000210 X-ray afterglow
  96. GRB 000210: BATSE Observations
  97. Correction to Chandra Position of GRB000210 afterglow
  98. Optical observations of the Chandra X-ray source for GRB000210
  99. GRB000210, Radio Observations
  100. Optical candidate for GRB000210

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