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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"

40744 results found.

  1. GRB 000615: NIR further observations
  2. GRB990123, HST/STIS observations of the host galaxy
  3. GRB000616 optical observations
  4. GRB 000615, near-infrared observations
  5. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  6. GRB000615, further R-band photometry
  7. GRB 000615: NIR observations
  8. GRB000615, R-band photometry
  9. GRB980425, HST/STIS observations of the host galaxy
  10. The Hosts of GRB 980703 and GRB 971214
  11. GRB 000301C: Further Late-Time HST/STIS observations
  12. GRB000528: follow-up X-ray measurements and update of IPN annulus
  13. Optical Follow-up of GRB000529 Error Box
  14. GRB980519, HST/STIS observations of the host galaxy
  15. GRB000607, Radio Observations
  16. GRB000604 optical non-detection
  17. GRB000604 - Optical observations
  18. GRB000607, A SHORT, HARD BURST
  19. GRB000604, optical observations
  20. GRB000528, optical observations at ESO
  21. GRB 000604 optical observations
  22. GRB 000418: Detection of the Host Galaxy
  23. GRB000604, optical observations, comparison with DPOSS
  24. GRB000528, Radio Observations
  25. X-ray Afterglow of GRB 000529
  26. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  27. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  28. IPN localization and time history of GRB000528
  29. New IPN localization of GRB000529
  30. GRB000519: Optical observations
  31. IPN localization of GRB000529
  32. GRB 000528 - WFC measurements
  33. GRB000528: BeppoSAX GRBM observations
  34. GRB 000528 Optical Observations
  35. GRB000519, BVRI field photometry
  36. IPN triangulation of GRB000519
  37. Re: GRB000508B : Optical observations
  38. GRB 000418, Optical observation
  39. GRB000508B, optical photometry
  40. GRB000508B, BVR field photometry
  41. Possible GRB-related phenomenon
  42. RXTE/ASM and IPN localization of GRB 000508B
  43. GRB000424, UBVRI field photometry
  44. GRB 000424 Optical Observations
  45. GRB000418, UBVRI field photometry update
  46. The redshift of GRB 000418
  47. GRB000424, optical observations
  48. GRB 000429, optical observation
  49. GRB 000429, UBVRI field photometry
  50. GRB 000418, UBVRI field photometry
  51. GRB000418, Radio detection
  52. GRB000418, K'-band photometry
  53. GRB 000418, Optical Observation
  54. GRB 000418, optical observation
  55. GRB000424 Optical Observations
  56. GRB 000418, Optical Observation
  57. GRB000424, optical observations
  58. GRB000424, optical observations
  59. GRB 000424, Optical Observations
  60. GRB 000418, Optical Observation
  61. GRB000418, near-infrared observations
  62. BeppoSAX GRB000424
  63. Correction to IPN error box for GRB000419
  64. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  65. GRB000416 BRJK observations
  66. 1SAXJ1715.0-7134 refined position
  67. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  68. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  69. Budget cuts in BeppoSAX operations: impact on GRB observations
  70. GRB 000408, optical observations
  71. Refined IPN error box for GRB000408
  72. GRB 991208, UBVRI field photometry
  73. GRB000301c results
  74. GRB000408: Optical CCD Observations from MIRO
  75. GRB000408, lotis optical observations
  76. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  77. GRB000326 Optical Observations
  78. GRB000301C - Addendum to GCN 623
  79. GRB000301C - R magnitude lower limit
  80. GRB000326, Further VLA observations
  81. GRB 000323, optical observations
  82. GRB 000326: Optical Observations
  83. GRB000326, Radio observations
  84. GRB 000307 optical observations
  85. Single error box for GRB000315
  86. GRB000315 [IPN Positions]
  87. GRB000313, Radio observations
  88. GRB 000313 - optical transient in the BATSE error box
  89. GRB000301C - B and R photometry
  90. GRB000301C - R photometry
  91. GRB 000307, Optical Observations
  92. GRB 000307, BVRI Field Photometry
  93. GRB 000301C: Optical Spectrum and Redshift
  94. GRB 000301C: Optical Spectrum and Redshift
  95. GRB 000301C: A Precise Redshift Determination
  96. GRB 000301C, Optical Observation
  97. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  98. GRB 000301C: HST/STIS CCD Imaging of the field
  99. GRB 000301c: K' observations
  100. GRB000301C, optical R-band observations

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