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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"

19424 results found.

  1. GRB001120: Gunn-i observations
  2. GRB001120, optical observations
  3. WSRT 4.8 GHz observations of GRB001109
  4. IPN triangulation of GRB001120
  5. GRB 001109: deep JHK upper limits
  6. GRB 001109 X-ray afterglow with BeppoSAX
  7. CORRECTION to XMM-Newton observation of GRB001025
  8. GRB001109, Radio observations
  9. GRB001105 BVRI field photometry correction
  10. GRB001105, BVRI field photometry
  11. GRB 001025B, Optical obervations
  12. GRB 991208: HST Imaging of the Host Galaxy
  13. GRB 001025B, I-band observations
  14. GRB001025B, Radio observations
  15. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  16. IPN triangulation of GRB001025
  17. GRB001007: Optical observations
  18. ASM Localization of GRB 001025
  19. GRB001007, Radio observations
  20. IPN TRIANGULATION OF GRB001020
  21. GRB001018, Gamma Ray Observations
  22. V,R,I band observations of GRB000926
  23. The Likely Optical/Infrared Afterglow of GRB 001011
  24. HETE positions added to GCN
  25. BeppoSAX ALERT: GRB001011
  26. GRB000926 - Amateur Optical Observations
  27. CONCAM null result on GRB001005
  28. IPN triangulation of GRB001007
  29. IPN triangulation of GRB001005
  30. GRB 000926 Chandra Observation
  31. IPN triangulation of GRB 001004
  32. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  33. GRB000926 - Optical observations
  34. GRB000926 - Optical observations
  35. GRB 000926, Optical Observations
  36. GRB000926 K'-band Observation
  37. J and K band observations of GRB 000926
  38. GRB 000926, optical observation by Oksanen (vsnet-grb)
  39. CONCAM crude optical limits before and after GRB000926
  40. Spectroscopic Redshift of GRB 000926
  41. GRB 000926: Optical candidate
  42. Optical candidate for GRB000926
  43. IPN triangulation of GRB000926
  44. GRB 000911, BVRI field photometry
  45. IPN triangulation of GRB000925
  46. GRB000911: Optical Transient
  47. GRB000911, Radio and Optical observations
  48. GRB000911: Optical observations
  49. IPN triangulation of GRB000911
  50. GRB000830, BVRI field photometry
  51. Chandra Position of GRB000210
  52. IPN localization of GRB000820
  53. SGR 1806-20 burst activity
  54. GRB000730, Gamma Ray Observations
  55. IPN localization of GRB000812
  56. IPN localization of GRB000811
  57. GRB000801, Gamma Ray Observations
  58. GRB000801, VLT-Antu R-band observations
  59. GRB 991208 Host Galaxy Imaging
  60. IPN localization of GRB000801
  61. IPN localization of GRB000730B
  62. GRB 990510: Possible detection of a host galaxy
  63. GRB 990510 Host Galaxy Discovery
  64. GRB 990705, HST/STIS observations of the host galaxy
  65. GRB 990712: Late time HST/STIS Observations
  66. GRB 991216, HST/STIS observations
  67. GRB000630, optical observations
  68. GRB000630, Revised BVRI Field Photometry
  69. GRB000630, Optical Observations
  70. GRB000630, optical observations
  71. GRB000630, optical observations
  72. GRB000630, BVRI Field Photometry
  73. GRB000630, optical observations
  74. GRB000630: Optical observations
  75. possible optical counterpart of GRB 000630
  76. IPN triangulation of GRB000630
  77. GRB 000620, optical observations
  78. GRB000418, HST/STIS Observations
  79. GRB990123: Late-time HST/STIS observations of the host
  80. GRB000623
  81. GRB000620, optical observations
  82. GRB000615: H-band observations
  83. GRB000620 - Optical observations
  84. GRB000620 Optical observations
  85. GRB000620: BeppoSAX WFC and GRBM detection
  86. GRB000615, Radio observations
  87. GRB000607, optical observations
  88. GRB 000615: NIR further observations
  89. BeppoSAX ALERT: GRB000620
  90. GRB000620: BeppoSAX Alert
  91. GRB000616 optical observations
  92. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  93. GRB000615, further R-band photometry
  94. GRB 000615: NIR observations
  95. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  96. GRB000615, R-band photometry
  97. GRB000615: BeppoSAX GRB Alert
  98. The Hosts of GRB 980703 and GRB 971214
  99. GRB 000301C: Further Late-Time HST/STIS observations
  100. GRB000528: follow-up X-ray measurements and update of IPN annulus

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