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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"

36800 results found.

  1. IPN localization of GRB000727
  2. GRB 990705, HST/STIS observations of the host galaxy
  3. GRB 990712: Late time HST/STIS Observations
  4. GRB 991216, HST/STIS observations
  5. GRB981226, HST/STIS observations of the host galaxy
  6. GRB 000630: Detection of the Optical Afterglow
  7. GRB000630, Revised BVRI Field Photometry
  8. GRB000630, Optical Observations
  9. GRB000630, optical observations
  10. GRB000630, BVRI Field Photometry
  11. GRB000630, optical observations
  12. GRB000630: Optical observations
  13. possible optical counterpart of GRB 000630
  14. IPN triangulation of GRB000630
  15. GRB 000623, optical observations
  16. GRB 000620, optical observations
  17. GRB000418, HST/STIS Observations
  18. GRB990123: Late-time HST/STIS observations of the host
  19. GRB 990506, HST/STIS Observations of the Host Galaxy
  20. GRB000623
  21. GRB 000620: J-band observations
  22. GRB990308, HST/STIS observations of the host galaxy
  23. IPN annulus for GRB000620
  24. GRB000615, Radio observations
  25. GRB000607, optical observations
  26. GRB 000615: NIR further observations
  27. BeppoSAX ALERT: GRB000620
  28. GRB000620: BeppoSAX Alert
  29. GRB990123, HST/STIS observations of the host galaxy
  30. GRB 000615, near-infrared observations
  31. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  32. GRB000616 [IPN Position]
  33. GRB000615B [IPN Position]
  34. GRB000615, further R-band photometry
  35. GRB 000615: NIR observations
  36. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  37. GRB000615, R-band photometry
  38. GRB980425, HST/STIS observations of the host galaxy
  39. GRB000615: BeppoSAX GRB Alert
  40. The Hosts of GRB 980703 and GRB 971214
  41. GRB 000301C: Further Late-Time HST/STIS observations
  42. GRB000528: follow-up X-ray measurements and update of IPN annulus
  43. GRB980519, HST/STIS observations of the host galaxy
  44. GRB000607, Radio Observations
  45. GRB000604 - Optical observations
  46. GRB000607, A SHORT, HARD BURST
  47. GRB000604, optical observations
  48. GRB000528, optical observations at ESO
  49. GRB 000604 optical observations
  50. GRB 000418: Detection of the Host Galaxy
  51. GRB000604, optical observations, comparison with DPOSS
  52. GRB000604 [IPN Position]
  53. X-ray Afterglow of GRB 000529
  54. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  55. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  56. IPN localization and time history of GRB000528
  57. New IPN localization of GRB000529
  58. GRB 000528 - WFC measurements
  59. GRB000528: BeppoSAX GRBM observations
  60. GRB 000528 Optical Observations
  61. GRB000519, BVRI field photometry
  62. IPN triangulation of GRB000519
  63. IPN triangulation of GRB000516
  64. Re: GRB000508B : Optical observations
  65. GRB 000418, Optical observation
  66. GRB000508B, optical photometry
  67. GRB000508B, BVR field photometry
  68. Possible GRB-related phenomenon
  69. RXTE/ASM and IPN localization of GRB 000508B
  70. GRB000424, UBVRI field photometry
  71. GRB 000424 Optical Observations
  72. GRB000418, UBVRI field photometry update
  73. The redshift of GRB 000418
  74. GRB 000429, optical observation
  75. GRB 000429, UBVRI field photometry
  76. IPN localization of GRB000429
  77. GRB 000418, UBVRI field photometry
  78. GRB000418, K'-band photometry
  79. GRB 000418, Optical Observation
  80. GRB 000418, optical observation
  81. GRB000424 Optical Observations
  82. GRB 000418, Optical Observation
  83. GRB 000424, Optical Observations
  84. GRB 000418, Optical Observation
  85. GRB000418, near-infrared observations
  86. Correction to IPN error box for GRB000419
  87. IPN error box for GRB000418
  88. GRB000419 [IPN Position]
  89. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  90. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  91. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  92. Budget cuts in BeppoSAX operations: impact on GRB observations
  93. GRB 000408, optical observations
  94. Refined IPN error box for GRB000408
  95. GRB 991208, UBVRI field photometry
  96. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  97. GRB000408 [IPN Position]
  98. GRB000326 Optical Observations
  99. GRB000301C - Addendum to GCN 623
  100. GRB000301C - R magnitude lower limit

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