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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"

32424 results found.

  1. Chandra Position of GRB000210
  2. "Snapshot" afterglow IDs and GRB 000830
  3. IPN triangulation of GRB000830
  4. HST/STIS observations of the host galaxy of GRB 980329
  5. HST/STIS observations of the chaotic environment of GRB 980613
  6. IPN localization of GRB000820
  7. GRB000801 & GRB000730, Gamma Ray Observations
  8. GRB000730, Gamma Ray Observations
  9. GRB000812, Radio observations
  10. IPN localization of GRB000812
  11. IPN localization of GRB000811
  12. GRB000801, Gamma Ray Observations
  13. GRB000801, VLT-Antu R-band observations
  14. GRB 991208 Host Galaxy Imaging
  15. Updated IPN coordinates for GRB000801
  16. IPN localization of GRB000801
  17. IPN localization of GRB000730B
  18. IPN localization of GRB000730B
  19. IPN localization of GRB000730
  20. GRB 990510: Possible detection of a host galaxy
  21. GRB 990510 Host Galaxy Discovery
  22. GRB 000727, optical observations
  23. IPN localization of GRB000727
  24. GRB 990705, HST/STIS observations of the host galaxy
  25. GRB 990712: Late time HST/STIS Observations
  26. GRB 991216, HST/STIS observations
  27. GRB981226, HST/STIS observations of the host galaxy
  28. GRB 000630: Detection of the Optical Afterglow
  29. GRB000630, Revised BVRI Field Photometry
  30. GRB000630, Optical Observations
  31. GRB000630, optical observations
  32. GRB000630, BVRI Field Photometry
  33. GRB000630, optical observations
  34. GRB000630: Optical observations
  35. possible optical counterpart of GRB 000630
  36. IPN triangulation of GRB000630
  37. GRB 000623, optical observations
  38. GRB 000620, optical observations
  39. GRB000418, HST/STIS Observations
  40. GRB990123: Late-time HST/STIS observations of the host
  41. GRB 990506, HST/STIS Observations of the Host Galaxy
  42. GRB000623
  43. GRB 000620: J-band observations
  44. GRB990308, HST/STIS observations of the host galaxy
  45. IPN annulus for GRB000620
  46. GRB000615, Radio observations
  47. GRB000607, optical observations
  48. GRB 000615: NIR further observations
  49. BeppoSAX ALERT: GRB000620
  50. GRB000620: BeppoSAX Alert
  51. GRB990123, HST/STIS observations of the host galaxy
  52. GRB 000615, near-infrared observations
  53. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  54. GRB000616 [IPN Position]
  55. GRB000615B [IPN Position]
  56. GRB000615, further R-band photometry
  57. GRB 000615: NIR observations
  58. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  59. GRB000615, R-band photometry
  60. GRB980425, HST/STIS observations of the host galaxy
  61. GRB000615: BeppoSAX GRB Alert
  62. The Hosts of GRB 980703 and GRB 971214
  63. GRB 000301C: Further Late-Time HST/STIS observations
  64. GRB000528: follow-up X-ray measurements and update of IPN annulus
  65. GRB980519, HST/STIS observations of the host galaxy
  66. GRB000607, Radio Observations
  67. GRB000604 - Optical observations
  68. GRB000607, A SHORT, HARD BURST
  69. GRB000604, optical observations
  70. GRB000528, optical observations at ESO
  71. GRB 000604 optical observations
  72. GRB 000418: Detection of the Host Galaxy
  73. GRB000604, optical observations, comparison with DPOSS
  74. GRB000604 [IPN Position]
  75. X-ray Afterglow of GRB 000529
  76. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  77. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  78. IPN localization and time history of GRB000528
  79. New IPN localization of GRB000529
  80. GRB 000528 - WFC measurements
  81. GRB000528: BeppoSAX GRBM observations
  82. GRB 000528 Optical Observations
  83. GRB000519, BVRI field photometry
  84. IPN triangulation of GRB000519
  85. IPN triangulation of GRB000516
  86. Re: GRB000508B : Optical observations
  87. GRB 000418, Optical observation
  88. GRB000508B, optical photometry
  89. GRB000508B, BVR field photometry
  90. Possible GRB-related phenomenon
  91. RXTE/ASM and IPN localization of GRB 000508B
  92. GRB000424, UBVRI field photometry
  93. GRB 000424 Optical Observations
  94. GRB000418, UBVRI field photometry update
  95. The redshift of GRB 000418
  96. GRB 000429, optical observation
  97. GRB 000429, UBVRI field photometry
  98. IPN localization of GRB000429
  99. GRB 000418, UBVRI field photometry
  100. GRB000418, K'-band photometry

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