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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"

32510 results found.

  1. GRB990123, HST/STIS observations of the host galaxy
  2. GRB000616 optical observations
  3. GRB 000615, near-infrared observations
  4. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  5. GRB000615, further R-band photometry
  6. GRB 000615: NIR observations
  7. GRB000615, R-band photometry
  8. GRB980425, HST/STIS observations of the host galaxy
  9. The Hosts of GRB 980703 and GRB 971214
  10. GRB 000301C: Further Late-Time HST/STIS observations
  11. GRB000528: follow-up X-ray measurements and update of IPN annulus
  12. Optical Follow-up of GRB000529 Error Box
  13. GRB000607, Radio Observations
  14. GRB000604 optical non-detection
  15. GRB000604 - Optical observations
  16. GRB000604, optical observations
  17. GRB000528, optical observations at ESO
  18. GRB 000604 optical observations
  19. GRB 000418: Detection of the Host Galaxy
  20. GRB000604, optical observations, comparison with DPOSS
  21. GRB000528, Radio Observations
  22. X-ray Afterglow of GRB 000529
  23. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  24. IPN localization and time history of GRB000528
  25. New IPN localization of GRB000529
  26. GRB000519: Optical observations
  27. IPN localization of GRB000529
  28. GRB 000528 - WFC measurements
  29. IPN triangulation of GRB000519
  30. Re: GRB000508B : Optical observations
  31. GRB 000418, Optical observation
  32. GRB000508B, optical photometry
  33. Possible GRB-related phenomenon
  34. GRB 000424 Optical Observations
  35. The redshift of GRB 000418
  36. GRB000424, optical observations
  37. GRB 000429, optical observation
  38. GRB000418, Radio detection
  39. GRB000418, K'-band photometry
  40. GRB 000418, Optical Observation
  41. GRB 000418, optical observation
  42. GRB000424 Optical Observations
  43. GRB 000418, Optical Observation
  44. GRB000424, optical observations
  45. GRB000424, optical observations
  46. GRB 000424, Optical Observations
  47. GRB 000418, Optical Observation
  48. GRB000418, near-infrared observations
  49. BeppoSAX GRB000424
  50. Correction to IPN error box for GRB000419
  51. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  52. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  53. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  54. GRB 000408, optical observations
  55. Refined IPN error box for GRB000408
  56. GRB000301c results
  57. GRB000408: Optical CCD Observations from MIRO
  58. GRB000408, lotis optical observations
  59. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  60. GRB000326 Optical Observations
  61. GRB000301C - Addendum to GCN 623
  62. GRB000326, Further VLA observations
  63. GRB 000323, optical observations
  64. GRB 000326: Optical Observations
  65. GRB000326, Radio observations
  66. GRB 000307 optical observations
  67. Single error box for GRB000315
  68. GRB000313, Radio observations
  69. GRB000301C - B and R photometry
  70. GRB 000307, Optical Observations
  71. GRB 000301C: Optical Spectrum and Redshift
  72. GRB 000301C: Optical Spectrum and Redshift
  73. GRB 000301C: A Precise Redshift Determination
  74. GRB 000301C, Optical Observation
  75. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  76. GRB 000301C: HST/STIS CCD Imaging of the field
  77. GRB000301C, optical R-band observations
  78. GRB000301c - R photometry and nearby faint source confirmation
  79. GRB 000301C, Optical Observation
  80. GRB 000301C Optical Observations
  81. GRB 000301C: K' Observations
  82. GRB000301C OT candidate optical observations
  83. Optical observations of GRB000301c
  84. GRB000301C, Radio observations
  85. GRB000301C, Radio observations
  86. GRB000301C, near-infrared observations (JHK' imaging)
  87. GRB 000301C, Optical Color
  88. GRB 000301C, UBVRI field photometry
  89. GRB 000301C, Optical Observation
  90. GRB000301C, optical observations
  91. GRB000301C 250 GHz detection
  92. GRB 000301C R-band observation
  93. GRB 000301C, Optical Observation
  94. GRB000301C, near-infrared observations (JHK' photometry)
  95. GRB 000301C: OT confirmed
  96. GRB000301c optical observations
  97. GRB 000301A, Radio Observations
  98. GRB000301C, optical observations
  99. GRB000301c, near-infrared observations
  100. GRB000301C

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