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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"

28048 results found.

  1. GRB 001025B, I-band observations
  2. XMM-Newton observation of GRB001025
  3. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  4. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  5. GRB001007: Optical observations
  6. ASM Localization of GRB 001025
  7. GRB001007, Radio observations
  8. GRB 001018, Possible Radio Afterglow
  9. GRB001018, Gamma Ray Observations
  10. IPN TRIANGULATION OF GRB001019
  11. IPN TRIANGULATION OF GRB001018
  12. IPN TRIANGULATION OF GRB 001017
  13. V,R,I band observations of GRB000926
  14. HETE positions added to GCN
  15. GRB000926 - Amateur Optical Observations
  16. CONCAM null result on GRB001005
  17. IPN triangulation of GRB001005
  18. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  19. GRB000926 - Optical observations
  20. GRB000926 - Optical observations
  21. GRB 000926, Optical Decay
  22. GRB000911: VLT infrared observation
  23. GRB 000926, Optical Observations
  24. GRB000926 K'-band Observation
  25. J and K band observations of GRB 000926
  26. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  27. CONCAM crude optical limits before and after GRB000926
  28. GRB 000926: Preliminary R-band Lightcurve
  29. Spectroscopic Redshift of GRB 000926
  30. GRB 000926: Optical candidate
  31. Optical candidate for GRB000926
  32. GRB 000911, BVRI field photometry
  33. GRB000911, Radio and Optical observations
  34. GRB000911: Optical observations
  35. GRB000830, BVRI field photometry
  36. GRB000210, Optical observations
  37. "Snapshot" afterglow IDs and GRB 000830
  38. GRB000730, Gamma Ray Observations
  39. GRB000812, Radio observations
  40. GRB000801, Gamma Ray Observations
  41. GRB000801, VLT-Antu R-band observations
  42. GRB 991208 Host Galaxy Imaging
  43. IPN localization of GRB000730B
  44. GRB 990510: Possible detection of a host galaxy
  45. GRB 990510 Host Galaxy Discovery
  46. IPN localization of GRB000727
  47. GRB 990712: Late time HST/STIS Observations
  48. GRB 991216, HST/STIS observations
  49. GRB000620, Radio Observations
  50. GRB000630, optical observations
  51. GRB000630, Revised BVRI Field Photometry
  52. GRB000630, Optical Observations
  53. GRB000630, optical observations
  54. GRB000630, optical observations
  55. GRB000630, BVRI Field Photometry
  56. GRB000630, optical observations
  57. GRB000630: Optical observations
  58. GRB000630, Radio Observations
  59. possible optical counterpart of GRB 000630
  60. GRB 000620, optical observations
  61. GRB000418, HST/STIS Observations
  62. GRB990123: Late-time HST/STIS observations of the host
  63. GRB000620, optical observations
  64. GRB000615: H-band observations
  65. GRB990308, HST/STIS observations of the host galaxy
  66. GRB000620 - Optical observations
  67. GRB000620 Optical observations
  68. GRB000620: BeppoSAX WFC and GRBM detection
  69. GRB000607, optical observations
  70. GRB 000615: NIR further observations
  71. GRB990123, HST/STIS observations of the host galaxy
  72. GRB000616 optical observations
  73. GRB 000615, near-infrared observations
  74. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  75. GRB000615, further R-band photometry
  76. GRB 000615: NIR observations
  77. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  78. GRB000615, R-band photometry
  79. The Hosts of GRB 980703 and GRB 971214
  80. GRB 000301C: Further Late-Time HST/STIS observations
  81. GRB000528: follow-up X-ray measurements and update of IPN annulus
  82. GRB980519, HST/STIS observations of the host galaxy
  83. GRB000604 optical non-detection
  84. GRB000604 - Optical observations
  85. GRB000604, optical observations
  86. GRB000528, optical observations at ESO
  87. GRB 000604 optical observations
  88. GRB 000418: Detection of the Host Galaxy
  89. GRB000604, optical observations, comparison with DPOSS
  90. GRB000528, Radio Observations
  91. X-ray Afterglow of GRB 000529
  92. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  93. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  94. GRB 000528 - WFC measurements
  95. GRB000519, BVRI field photometry
  96. IPN triangulation of GRB000519
  97. GRB000508B, optical photometry
  98. GRB000508B, BVR field photometry
  99. Possible GRB-related phenomenon
  100. RXTE/ASM and IPN localization of GRB 000508B

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