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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"

26326 results found.

  1. GRB 000926, Optical Observations
  2. GRB000926 K'-band Observation
  3. J and K band observations of GRB 000926
  4. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  5. CONCAM crude optical limits before and after GRB000926
  6. GRB 000926: Preliminary R-band Lightcurve
  7. Spectroscopic Redshift of GRB 000926
  8. GRB 000926: Optical candidate
  9. Optical candidate for GRB000926
  10. GRB 000911, BVRI field photometry
  11. GRB000911, Radio and Optical observations
  12. GRB000911: Optical observations
  13. GRB000830, BVRI field photometry
  14. GRB000210, Optical observations
  15. "Snapshot" afterglow IDs and GRB 000830
  16. GRB000730, Gamma Ray Observations
  17. GRB000812, Radio observations
  18. GRB000801, Gamma Ray Observations
  19. GRB000801, VLT-Antu R-band observations
  20. GRB 991208 Host Galaxy Imaging
  21. IPN localization of GRB000730B
  22. GRB 990510: Possible detection of a host galaxy
  23. GRB 990510 Host Galaxy Discovery
  24. IPN localization of GRB000727
  25. GRB 990712: Late time HST/STIS Observations
  26. GRB 991216, HST/STIS observations
  27. GRB000620, Radio Observations
  28. GRB000630, optical observations
  29. GRB000630, Revised BVRI Field Photometry
  30. GRB000630, Optical Observations
  31. GRB000630, optical observations
  32. GRB000630, optical observations
  33. GRB000630, BVRI Field Photometry
  34. GRB000630, optical observations
  35. GRB000630: Optical observations
  36. GRB000630, Radio Observations
  37. possible optical counterpart of GRB 000630
  38. GRB 000620, optical observations
  39. GRB000418, HST/STIS Observations
  40. GRB990123: Late-time HST/STIS observations of the host
  41. GRB000620, optical observations
  42. GRB000615: H-band observations
  43. GRB990308, HST/STIS observations of the host galaxy
  44. GRB000620 - Optical observations
  45. GRB000620 Optical observations
  46. GRB000620: BeppoSAX WFC and GRBM detection
  47. GRB000607, optical observations
  48. GRB 000615: NIR further observations
  49. GRB990123, HST/STIS observations of the host galaxy
  50. GRB000616 optical observations
  51. GRB 000615, near-infrared observations
  52. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  53. GRB000615, further R-band photometry
  54. GRB 000615: NIR observations
  55. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  56. GRB000615, R-band photometry
  57. The Hosts of GRB 980703 and GRB 971214
  58. GRB 000301C: Further Late-Time HST/STIS observations
  59. GRB000528: follow-up X-ray measurements and update of IPN annulus
  60. GRB980519, HST/STIS observations of the host galaxy
  61. GRB000604 optical non-detection
  62. GRB000604 - Optical observations
  63. GRB000604, optical observations
  64. GRB000528, optical observations at ESO
  65. GRB 000604 optical observations
  66. GRB 000418: Detection of the Host Galaxy
  67. GRB000604, optical observations, comparison with DPOSS
  68. GRB000528, Radio Observations
  69. X-ray Afterglow of GRB 000529
  70. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  71. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  72. GRB 000528 - WFC measurements
  73. GRB000519, BVRI field photometry
  74. IPN triangulation of GRB000519
  75. GRB000508B, optical photometry
  76. GRB000508B, BVR field photometry
  77. Possible GRB-related phenomenon
  78. RXTE/ASM and IPN localization of GRB 000508B
  79. GRB000424, UBVRI field photometry
  80. GRB000418, UBVRI field photometry update
  81. GRB000424, optical observations
  82. GRB 000429, optical observation
  83. GRB 000429, UBVRI field photometry
  84. GRB 000418, UBVRI field photometry
  85. GRB 000418, optical observation
  86. GRB 000418, Optical Observation
  87. GRB000418, near-infrared observations
  88. Correction to IPN error box for GRB000419
  89. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  90. GRB000416 BRJK observations
  91. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  92. GRB 000408, optical observations
  93. GRB 991208, UBVRI field photometry
  94. GRB000408, lotis optical observations
  95. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  96. GRB000301C - Addendum to GCN 623
  97. GRB 000323, optical observations
  98. GRB 000326: Optical Observations
  99. GRB000326, Radio observations
  100. GRB000313, Radio observations

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