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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"

37499 results found.

  1. GRB 990705, HST/STIS observations of the host galaxy
  2. GRB 990712: Late time HST/STIS Observations
  3. GRB 991216, HST/STIS observations
  4. GRB981226, HST/STIS observations of the host galaxy
  5. GRB 000630: Detection of the Optical Afterglow
  6. GRB000630, Revised BVRI Field Photometry
  7. GRB000630, Optical Observations
  8. GRB000630, optical observations
  9. GRB000630, BVRI Field Photometry
  10. GRB000630, optical observations
  11. GRB000630: Optical observations
  12. possible optical counterpart of GRB 000630
  13. IPN triangulation of GRB000630
  14. GRB 000623, optical observations
  15. GRB 000620, optical observations
  16. GRB000418, HST/STIS Observations
  17. GRB990123: Late-time HST/STIS observations of the host
  18. GRB 990506, HST/STIS Observations of the Host Galaxy
  19. GRB000623
  20. GRB 000620: J-band observations
  21. GRB990308, HST/STIS observations of the host galaxy
  22. IPN annulus for GRB000620
  23. GRB000615, Radio observations
  24. GRB000607, optical observations
  25. GRB 000615: NIR further observations
  26. BeppoSAX ALERT: GRB000620
  27. GRB000620: BeppoSAX Alert
  28. GRB990123, HST/STIS observations of the host galaxy
  29. GRB 000615, near-infrared observations
  30. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  31. GRB000616 [IPN Position]
  32. GRB000615B [IPN Position]
  33. GRB000615, further R-band photometry
  34. GRB 000615: NIR observations
  35. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  36. GRB000615, R-band photometry
  37. GRB980425, HST/STIS observations of the host galaxy
  38. GRB000615: BeppoSAX GRB Alert
  39. The Hosts of GRB 980703 and GRB 971214
  40. GRB 000301C: Further Late-Time HST/STIS observations
  41. GRB000528: follow-up X-ray measurements and update of IPN annulus
  42. GRB980519, HST/STIS observations of the host galaxy
  43. GRB000607, Radio Observations
  44. GRB000604 - Optical observations
  45. GRB000607, A SHORT, HARD BURST
  46. GRB000604, optical observations
  47. GRB000528, optical observations at ESO
  48. GRB 000604 optical observations
  49. GRB 000418: Detection of the Host Galaxy
  50. GRB000604, optical observations, comparison with DPOSS
  51. GRB000604 [IPN Position]
  52. X-ray Afterglow of GRB 000529
  53. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  54. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  55. IPN localization and time history of GRB000528
  56. New IPN localization of GRB000529
  57. GRB 000528 - WFC measurements
  58. GRB000528: BeppoSAX GRBM observations
  59. GRB 000528 Optical Observations
  60. GRB000519, BVRI field photometry
  61. IPN triangulation of GRB000519
  62. IPN triangulation of GRB000516
  63. Re: GRB000508B : Optical observations
  64. GRB 000418, Optical observation
  65. GRB000508B, optical photometry
  66. GRB000508B, BVR field photometry
  67. Possible GRB-related phenomenon
  68. RXTE/ASM and IPN localization of GRB 000508B
  69. GRB000424, UBVRI field photometry
  70. GRB 000424 Optical Observations
  71. GRB000418, UBVRI field photometry update
  72. The redshift of GRB 000418
  73. GRB 000429, optical observation
  74. GRB 000429, UBVRI field photometry
  75. IPN localization of GRB000429
  76. GRB 000418, UBVRI field photometry
  77. GRB000418, K'-band photometry
  78. GRB 000418, Optical Observation
  79. GRB 000418, optical observation
  80. GRB000424 Optical Observations
  81. GRB 000418, Optical Observation
  82. GRB 000424, Optical Observations
  83. GRB 000418, Optical Observation
  84. GRB000418, near-infrared observations
  85. Correction to IPN error box for GRB000419
  86. IPN error box for GRB000418
  87. GRB000419 [IPN Position]
  88. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  89. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  90. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  91. Budget cuts in BeppoSAX operations: impact on GRB observations
  92. GRB 000408, optical observations
  93. Refined IPN error box for GRB000408
  94. GRB 991208, UBVRI field photometry
  95. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  96. GRB000408 [IPN Position]
  97. GRB000326 Optical Observations
  98. GRB000301C - Addendum to GCN 623
  99. GRB000301C - R magnitude lower limit
  100. GRB 000323, optical observations

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