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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"

15994 results found.

  1. GRB 001025A, optical observation
  2. GRB001007: Optical observations
  3. GRB001007, Radio observations
  4. GRB001019, Optical Observations
  5. GRB 000926: Improved Absorber Redshift
  6. The Likely Optical/Infrared Afterglow of GRB 001011
  7. GRB 001007, BVR-band observations
  8. GRB000926 - Amateur Optical Observations
  9. GRB001007: Optical observations
  10. CONCAM null result on GRB001005
  11. GRB 000926 : the host galaxy
  12. GRB 000926 Chandra Observation
  13. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  14. GRB000926 - Optical observations
  15. GRB000926 - Optical observations
  16. GRB 000926, Optical Decay
  17. GRB000911: VLT infrared observation
  18. GRB000926 - Optical observations
  19. GRB000926 - Optical observations
  20. GRB 000926: optical observations
  21. GRB 000926, Optical Observations
  22. GRB000926 - Optical observations
  23. GRB000911: optical VLT observations
  24. GRB000926 K'-band Observation
  25. GRB000926 : increasing optical decay slope
  26. GRB000926 optical observations
  27. GRB000926 - Optical observations
  28. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  29. J and K band observations of GRB 000926
  30. GRB000911 Optical Observations
  31. GRB 000926: Lightcurve Update and Predictions
  32. GRB 000926, optical observation by Oksanen (vsnet-grb)
  33. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  34. GRB000926: Optical observations
  35. CONCAM crude optical limits before and after GRB000926
  36. GRB 000926: Preliminary R-band Lightcurve
  37. GRB 000926 HST/Chandra TOO Status
  38. Spectroscopic Redshift of GRB 000926
  39. GRB 000926, Optical Observation
  40. GRB000926, radio observations
  41. GRB 000926: Optical candidate
  42. Optical candidate for GRB000926
  43. GRB 000911, BVRI field photometry
  44. GRB000911: Sub-millimeter observations
  45. GRB000911: Optical Transient
  46. GRB000911, Radio and Optical observations
  47. GRB000911: Optical observations
  48. GRB 000830: Optical observations
  49. GRB000830: Optical observations
  50. GRB000830, TNG B-band observations
  51. GRB000830, BVRI field photometry
  52. GRB000830: Optical observations
  53. GRB000210, Optical observations
  54. Chandra Position of GRB000210
  55. "Snapshot" afterglow IDs and GRB 000830
  56. GRB000830: Optical observations
  57. HST/STIS observations of the host galaxy of GRB 980329
  58. HST/STIS observations of the chaotic environment of GRB 980613
  59. GRB000812, TNG R-band observations
  60. GRB000801, VLT-Antu R-band observations
  61. GRB000301C, UBVI optical observations
  62. GRB 000727, optical observations
  63. GRB 990712: Late time HST/STIS Observations
  64. GRB000630, optical observations
  65. GRB 000630: Detection of the Optical Afterglow
  66. GRB000630, Optical Observations
  67. GRB000630, optical observations
  68. GRB000630, optical observations
  69. GRB000630, BVRI Field Photometry
  70. GRB000630, optical observations
  71. GRB000630, optical observations
  72. GRB000630: Optical observations
  73. GRB000630, Radio Observations
  74. possible optical counterpart of GRB 000630
  75. GRB 000623, optical observations
  76. GRB 000620, optical observations
  77. GRB000418, HST/STIS Observations
  78. GRB 990506, HST/STIS Observations of the Host Galaxy
  79. GRB000620, optical observations
  80. GRB990308, HST/STIS observations of the host galaxy
  81. GRB000620 - Optical observations
  82. GRB000620 Optical observations
  83. GRB000607, optical observations
  84. GRB990123, HST/STIS observations of the host galaxy
  85. GRB000616 optical observations
  86. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  87. GRB000615, further R-band photometry
  88. The Hosts of GRB 980703 and GRB 971214
  89. GRB 000301C: Further Late-Time HST/STIS observations
  90. Optical Follow-up of GRB000529 Error Box
  91. GRB000604 optical non-detection
  92. GRB000604 - Optical observations
  93. GRB000604, optical observations
  94. GRB000528, optical observations at ESO
  95. GRB 000604 optical observations
  96. GRB 000418: Detection of the Host Galaxy
  97. GRB000604, optical observations, comparison with DPOSS
  98. GRB000529: Optical Observations
  99. GRB000519: Optical observations
  100. GRB 000528 Optical Observations

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