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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"

32506 results found.

  1. GRB000615, further R-band photometry
  2. GRB 000615: NIR observations
  3. GRB000615, R-band photometry
  4. GRB980425, HST/STIS observations of the host galaxy
  5. The Hosts of GRB 980703 and GRB 971214
  6. GRB 000301C: Further Late-Time HST/STIS observations
  7. GRB000528: follow-up X-ray measurements and update of IPN annulus
  8. Optical Follow-up of GRB000529 Error Box
  9. GRB000607, Radio Observations
  10. GRB000604 optical non-detection
  11. GRB000604 - Optical observations
  12. GRB000604, optical observations
  13. GRB000528, optical observations at ESO
  14. GRB 000604 optical observations
  15. GRB 000418: Detection of the Host Galaxy
  16. GRB000604, optical observations, comparison with DPOSS
  17. GRB000528, Radio Observations
  18. X-ray Afterglow of GRB 000529
  19. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  20. IPN localization and time history of GRB000528
  21. New IPN localization of GRB000529
  22. GRB000519: Optical observations
  23. IPN localization of GRB000529
  24. GRB 000528 - WFC measurements
  25. IPN triangulation of GRB000519
  26. Re: GRB000508B : Optical observations
  27. GRB 000418, Optical observation
  28. GRB000508B, optical photometry
  29. Possible GRB-related phenomenon
  30. GRB 000424 Optical Observations
  31. The redshift of GRB 000418
  32. GRB000424, optical observations
  33. GRB 000429, optical observation
  34. GRB000418, Radio detection
  35. GRB000418, K'-band photometry
  36. GRB 000418, Optical Observation
  37. GRB 000418, optical observation
  38. GRB000424 Optical Observations
  39. GRB 000418, Optical Observation
  40. GRB000424, optical observations
  41. GRB000424, optical observations
  42. GRB 000424, Optical Observations
  43. GRB 000418, Optical Observation
  44. GRB000418, near-infrared observations
  45. BeppoSAX GRB000424
  46. Correction to IPN error box for GRB000419
  47. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  48. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  49. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  50. GRB 000408, optical observations
  51. Refined IPN error box for GRB000408
  52. GRB000301c results
  53. GRB000408: Optical CCD Observations from MIRO
  54. GRB000408, lotis optical observations
  55. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  56. GRB000326 Optical Observations
  57. GRB000301C - Addendum to GCN 623
  58. GRB000326, Further VLA observations
  59. GRB 000323, optical observations
  60. GRB 000326: Optical Observations
  61. GRB000326, Radio observations
  62. GRB 000307 optical observations
  63. Single error box for GRB000315
  64. GRB000313, Radio observations
  65. GRB000301C - B and R photometry
  66. GRB 000307, Optical Observations
  67. GRB 000301C: Optical Spectrum and Redshift
  68. GRB 000301C: Optical Spectrum and Redshift
  69. GRB 000301C: A Precise Redshift Determination
  70. GRB 000301C, Optical Observation
  71. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  72. GRB 000301C: HST/STIS CCD Imaging of the field
  73. GRB000301C, optical R-band observations
  74. GRB000301c - R photometry and nearby faint source confirmation
  75. GRB 000301C, Optical Observation
  76. GRB 000301C Optical Observations
  77. GRB 000301C: K' Observations
  78. GRB000301C OT candidate optical observations
  79. Optical observations of GRB000301c
  80. GRB000301C, Radio observations
  81. GRB000301C, Radio observations
  82. GRB000301C, near-infrared observations (JHK' imaging)
  83. GRB 000301C, Optical Color
  84. GRB 000301C, UBVRI field photometry
  85. GRB 000301C, Optical Observation
  86. GRB000301C, optical observations
  87. GRB000301C 250 GHz detection
  88. GRB 000301C R-band observation
  89. GRB 000301C, Optical Observation
  90. GRB000301C, near-infrared observations (JHK' photometry)
  91. GRB 000301C: OT confirmed
  92. GRB000301c optical observations
  93. GRB 000301A, Radio Observations
  94. GRB000301C, optical observations
  95. GRB000301c, near-infrared observations
  96. GRB000301C
  97. GRB 000301C : Optical Candidate
  98. Radio observations of the error box of GRB000301A
  99. HST Observations of GRB 990712
  100. GRB 000115 Optical observations

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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