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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"

36793 results found.

  1. GRB000630, Optical Observations
  2. GRB000630, optical observations
  3. GRB000630, BVRI Field Photometry
  4. GRB000630, optical observations
  5. GRB000630: Optical observations
  6. possible optical counterpart of GRB 000630
  7. IPN triangulation of GRB000630
  8. GRB 000623, optical observations
  9. GRB 000620, optical observations
  10. GRB000418, HST/STIS Observations
  11. GRB990123: Late-time HST/STIS observations of the host
  12. GRB 990506, HST/STIS Observations of the Host Galaxy
  13. GRB000623
  14. GRB 000620: J-band observations
  15. GRB990308, HST/STIS observations of the host galaxy
  16. IPN annulus for GRB000620
  17. GRB000615, Radio observations
  18. GRB000607, optical observations
  19. GRB 000615: NIR further observations
  20. BeppoSAX ALERT: GRB000620
  21. GRB000620: BeppoSAX Alert
  22. GRB990123, HST/STIS observations of the host galaxy
  23. GRB 000615, near-infrared observations
  24. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  25. GRB000616 [IPN Position]
  26. GRB000615B [IPN Position]
  27. GRB000615, further R-band photometry
  28. GRB 000615: NIR observations
  29. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  30. GRB000615, R-band photometry
  31. GRB980425, HST/STIS observations of the host galaxy
  32. GRB000615: BeppoSAX GRB Alert
  33. The Hosts of GRB 980703 and GRB 971214
  34. GRB 000301C: Further Late-Time HST/STIS observations
  35. GRB000528: follow-up X-ray measurements and update of IPN annulus
  36. GRB980519, HST/STIS observations of the host galaxy
  37. GRB000607, Radio Observations
  38. GRB000604 - Optical observations
  39. GRB000607, A SHORT, HARD BURST
  40. GRB000604, optical observations
  41. GRB000528, optical observations at ESO
  42. GRB 000604 optical observations
  43. GRB 000418: Detection of the Host Galaxy
  44. GRB000604, optical observations, comparison with DPOSS
  45. GRB000604 [IPN Position]
  46. X-ray Afterglow of GRB 000529
  47. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  48. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  49. IPN localization and time history of GRB000528
  50. New IPN localization of GRB000529
  51. GRB 000528 - WFC measurements
  52. GRB000528: BeppoSAX GRBM observations
  53. GRB 000528 Optical Observations
  54. GRB000519, BVRI field photometry
  55. IPN triangulation of GRB000519
  56. IPN triangulation of GRB000516
  57. Re: GRB000508B : Optical observations
  58. GRB 000418, Optical observation
  59. GRB000508B, optical photometry
  60. GRB000508B, BVR field photometry
  61. Possible GRB-related phenomenon
  62. RXTE/ASM and IPN localization of GRB 000508B
  63. GRB000424, UBVRI field photometry
  64. GRB 000424 Optical Observations
  65. GRB000418, UBVRI field photometry update
  66. The redshift of GRB 000418
  67. GRB 000429, optical observation
  68. GRB 000429, UBVRI field photometry
  69. IPN localization of GRB000429
  70. GRB 000418, UBVRI field photometry
  71. GRB000418, K'-band photometry
  72. GRB 000418, Optical Observation
  73. GRB 000418, optical observation
  74. GRB000424 Optical Observations
  75. GRB 000418, Optical Observation
  76. GRB 000424, Optical Observations
  77. GRB 000418, Optical Observation
  78. GRB000418, near-infrared observations
  79. Correction to IPN error box for GRB000419
  80. IPN error box for GRB000418
  81. GRB000419 [IPN Position]
  82. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  83. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  84. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  85. Budget cuts in BeppoSAX operations: impact on GRB observations
  86. GRB 000408, optical observations
  87. Refined IPN error box for GRB000408
  88. GRB 991208, UBVRI field photometry
  89. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  90. GRB000408 [IPN Position]
  91. GRB000326 Optical Observations
  92. GRB000301C - Addendum to GCN 623
  93. GRB000301C - R magnitude lower limit
  94. GRB 000323, optical observations
  95. GRB 000326: Optical Observations
  96. GRB000326, Radio observations
  97. GRB000326 [IPN Position]
  98. GRB 000307 optical observations
  99. GRB000323 [IPN Position]
  100. GRB000315 [IPN Positions]

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