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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"

35937 results found.

  1. GRB 000926: Optical candidate
  2. Optical candidate for GRB000926
  3. IPN triangulation of GRB000926
  4. GRB 000911, BVRI field photometry
  5. GRB000911: Sub-millimeter observations
  6. IPN triangulation of GRB000925
  7. IPN triangulation of GRB000911
  8. IPN triangulation of GRB000910
  9. False GRB alarm from RXTE/ASM on 8 Sept 2000
  10. GRB 000830: Optical observations
  11. GRB000830: Optical observations
  12. GRB000830, TNG B-band observations
  13. GRB000830, BVRI field photometry
  14. GRB000830: Optical observations
  15. GRB000210, Optical observations
  16. Chandra Position of GRB000210
  17. "Snapshot" afterglow IDs and GRB 000830
  18. IPN triangulation of GRB000830
  19. HST/STIS observations of the host galaxy of GRB 980329
  20. HST/STIS observations of the chaotic environment of GRB 980613
  21. IPN localization of GRB000820
  22. GRB000801 & GRB000730, Gamma Ray Observations
  23. GRB000730, Gamma Ray Observations
  24. GRB000812, Radio observations
  25. IPN localization of GRB000812
  26. IPN localization of GRB000811
  27. GRB000801, Gamma Ray Observations
  28. GRB000801, VLT-Antu R-band observations
  29. GRB 991208 Host Galaxy Imaging
  30. Updated IPN coordinates for GRB000801
  31. IPN localization of GRB000801
  32. IPN localization of GRB000730B
  33. IPN localization of GRB000730B
  34. IPN localization of GRB000730
  35. GRB 990510: Possible detection of a host galaxy
  36. GRB 990510 Host Galaxy Discovery
  37. GRB 000727, optical observations
  38. IPN localization of GRB000727
  39. GRB 990705, HST/STIS observations of the host galaxy
  40. GRB 990712: Late time HST/STIS Observations
  41. GRB 991216, HST/STIS observations
  42. GRB981226, HST/STIS observations of the host galaxy
  43. GRB 000630: Detection of the Optical Afterglow
  44. GRB000630, Revised BVRI Field Photometry
  45. GRB000630, Optical Observations
  46. GRB000630, optical observations
  47. GRB000630, BVRI Field Photometry
  48. GRB000630, optical observations
  49. GRB000630: Optical observations
  50. possible optical counterpart of GRB 000630
  51. IPN triangulation of GRB000630
  52. GRB 000623, optical observations
  53. GRB 000620, optical observations
  54. GRB000418, HST/STIS Observations
  55. GRB990123: Late-time HST/STIS observations of the host
  56. GRB 990506, HST/STIS Observations of the Host Galaxy
  57. GRB000623
  58. GRB 000620: J-band observations
  59. GRB990308, HST/STIS observations of the host galaxy
  60. IPN annulus for GRB000620
  61. GRB000615, Radio observations
  62. GRB000607, optical observations
  63. GRB 000615: NIR further observations
  64. BeppoSAX ALERT: GRB000620
  65. GRB000620: BeppoSAX Alert
  66. GRB990123, HST/STIS observations of the host galaxy
  67. GRB 000615, near-infrared observations
  68. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  69. GRB000616 [IPN Position]
  70. GRB000615B [IPN Position]
  71. GRB000615, further R-band photometry
  72. GRB 000615: NIR observations
  73. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  74. GRB000615, R-band photometry
  75. GRB980425, HST/STIS observations of the host galaxy
  76. GRB000615: BeppoSAX GRB Alert
  77. The Hosts of GRB 980703 and GRB 971214
  78. GRB 000301C: Further Late-Time HST/STIS observations
  79. GRB000528: follow-up X-ray measurements and update of IPN annulus
  80. GRB980519, HST/STIS observations of the host galaxy
  81. GRB000607, Radio Observations
  82. GRB000604 - Optical observations
  83. GRB000607, A SHORT, HARD BURST
  84. GRB000604, optical observations
  85. GRB000528, optical observations at ESO
  86. GRB 000604 optical observations
  87. GRB 000418: Detection of the Host Galaxy
  88. GRB000604, optical observations, comparison with DPOSS
  89. GRB000604 [IPN Position]
  90. X-ray Afterglow of GRB 000529
  91. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  92. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  93. IPN localization and time history of GRB000528
  94. New IPN localization of GRB000529
  95. GRB 000528 - WFC measurements
  96. GRB000528: BeppoSAX GRBM observations
  97. GRB 000528 Optical Observations
  98. GRB000519, BVRI field photometry
  99. IPN triangulation of GRB000519
  100. IPN triangulation of GRB000516

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