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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"

32495 results found.

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

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