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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"

32801 results found.

  1. GRB 991216, HST/STIS observations
  2. GRB981226, HST/STIS observations of the host galaxy
  3. GRB 000630: Detection of the Optical Afterglow
  4. GRB000630, Revised BVRI Field Photometry
  5. GRB000630, Optical Observations
  6. GRB000630, optical observations
  7. GRB000630, BVRI Field Photometry
  8. GRB000630, optical observations
  9. GRB000630: Optical observations
  10. possible optical counterpart of GRB 000630
  11. IPN triangulation of GRB000630
  12. GRB 000623, optical observations
  13. GRB 000620, optical observations
  14. GRB000418, HST/STIS Observations
  15. GRB990123: Late-time HST/STIS observations of the host
  16. GRB 990506, HST/STIS Observations of the Host Galaxy
  17. GRB000623
  18. GRB 000620: J-band observations
  19. GRB990308, HST/STIS observations of the host galaxy
  20. IPN annulus for GRB000620
  21. GRB000615, Radio observations
  22. GRB000607, optical observations
  23. GRB 000615: NIR further observations
  24. BeppoSAX ALERT: GRB000620
  25. GRB000620: BeppoSAX Alert
  26. GRB990123, HST/STIS observations of the host galaxy
  27. GRB 000615, near-infrared observations
  28. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  29. GRB000616 [IPN Position]
  30. GRB000615B [IPN Position]
  31. GRB000615, further R-band photometry
  32. GRB 000615: NIR observations
  33. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  34. GRB000615, R-band photometry
  35. GRB980425, HST/STIS observations of the host galaxy
  36. GRB000615: BeppoSAX GRB Alert
  37. The Hosts of GRB 980703 and GRB 971214
  38. GRB 000301C: Further Late-Time HST/STIS observations
  39. GRB000528: follow-up X-ray measurements and update of IPN annulus
  40. GRB980519, HST/STIS observations of the host galaxy
  41. GRB000607, Radio Observations
  42. GRB000604 - Optical observations
  43. GRB000607, A SHORT, HARD BURST
  44. GRB000604, optical observations
  45. GRB000528, optical observations at ESO
  46. GRB 000604 optical observations
  47. GRB 000418: Detection of the Host Galaxy
  48. GRB000604, optical observations, comparison with DPOSS
  49. GRB000604 [IPN Position]
  50. X-ray Afterglow of GRB 000529
  51. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  52. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  53. IPN localization and time history of GRB000528
  54. New IPN localization of GRB000529
  55. GRB 000528 - WFC measurements
  56. GRB000528: BeppoSAX GRBM observations
  57. GRB 000528 Optical Observations
  58. GRB000519, BVRI field photometry
  59. IPN triangulation of GRB000519
  60. IPN triangulation of GRB000516
  61. Re: GRB000508B : Optical observations
  62. GRB 000418, Optical observation
  63. GRB000508B, optical photometry
  64. GRB000508B, BVR field photometry
  65. Possible GRB-related phenomenon
  66. RXTE/ASM and IPN localization of GRB 000508B
  67. GRB000424, UBVRI field photometry
  68. GRB 000424 Optical Observations
  69. GRB000418, UBVRI field photometry update
  70. The redshift of GRB 000418
  71. GRB 000429, optical observation
  72. GRB 000429, UBVRI field photometry
  73. IPN localization of GRB000429
  74. GRB 000418, UBVRI field photometry
  75. GRB000418, K'-band photometry
  76. GRB 000418, Optical Observation
  77. GRB 000418, optical observation
  78. GRB000424 Optical Observations
  79. GRB 000418, Optical Observation
  80. GRB 000424, Optical Observations
  81. GRB 000418, Optical Observation
  82. GRB000418, near-infrared observations
  83. Correction to IPN error box for GRB000419
  84. IPN error box for GRB000418
  85. GRB000419 [IPN Position]
  86. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  87. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  88. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  89. Budget cuts in BeppoSAX operations: impact on GRB observations
  90. GRB 000408, optical observations
  91. Refined IPN error box for GRB000408
  92. GRB 991208, UBVRI field photometry
  93. GRB000301c results
  94. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  95. GRB000408 [IPN Position]
  96. GRB000326 Optical Observations
  97. GRB000301C - Addendum to GCN 623
  98. GRB000301C - R magnitude lower limit
  99. GRB 000323, optical observations
  100. GRB 000326: Optical Observations

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