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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"

37943 results found.

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

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