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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"

36785 results found.

  1. GRB 000620, optical observations
  2. GRB000418, HST/STIS Observations
  3. GRB990123: Late-time HST/STIS observations of the host
  4. GRB 990506, HST/STIS Observations of the Host Galaxy
  5. GRB000623
  6. GRB 000620: J-band observations
  7. GRB990308, HST/STIS observations of the host galaxy
  8. IPN annulus for GRB000620
  9. GRB000615, Radio observations
  10. GRB000607, optical observations
  11. GRB 000615: NIR further observations
  12. BeppoSAX ALERT: GRB000620
  13. GRB000620: BeppoSAX Alert
  14. GRB990123, HST/STIS observations of the host galaxy
  15. GRB 000615, near-infrared observations
  16. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  17. GRB000616 [IPN Position]
  18. GRB000615B [IPN Position]
  19. GRB000615, further R-band photometry
  20. GRB 000615: NIR observations
  21. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  22. GRB000615, R-band photometry
  23. GRB980425, HST/STIS observations of the host galaxy
  24. GRB000615: BeppoSAX GRB Alert
  25. The Hosts of GRB 980703 and GRB 971214
  26. GRB 000301C: Further Late-Time HST/STIS observations
  27. GRB000528: follow-up X-ray measurements and update of IPN annulus
  28. GRB980519, HST/STIS observations of the host galaxy
  29. GRB000607, Radio Observations
  30. GRB000604 - Optical observations
  31. GRB000607, A SHORT, HARD BURST
  32. GRB000604, optical observations
  33. GRB000528, optical observations at ESO
  34. GRB 000604 optical observations
  35. GRB 000418: Detection of the Host Galaxy
  36. GRB000604, optical observations, comparison with DPOSS
  37. GRB000604 [IPN Position]
  38. X-ray Afterglow of GRB 000529
  39. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  40. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  41. IPN localization and time history of GRB000528
  42. New IPN localization of GRB000529
  43. GRB 000528 - WFC measurements
  44. GRB000528: BeppoSAX GRBM observations
  45. GRB 000528 Optical Observations
  46. GRB000519, BVRI field photometry
  47. IPN triangulation of GRB000519
  48. IPN triangulation of GRB000516
  49. Re: GRB000508B : Optical observations
  50. GRB 000418, Optical observation
  51. GRB000508B, optical photometry
  52. GRB000508B, BVR field photometry
  53. Possible GRB-related phenomenon
  54. RXTE/ASM and IPN localization of GRB 000508B
  55. GRB000424, UBVRI field photometry
  56. GRB 000424 Optical Observations
  57. GRB000418, UBVRI field photometry update
  58. The redshift of GRB 000418
  59. GRB 000429, optical observation
  60. GRB 000429, UBVRI field photometry
  61. IPN localization of GRB000429
  62. GRB 000418, UBVRI field photometry
  63. GRB000418, K'-band photometry
  64. GRB 000418, Optical Observation
  65. GRB 000418, optical observation
  66. GRB000424 Optical Observations
  67. GRB 000418, Optical Observation
  68. GRB 000424, Optical Observations
  69. GRB 000418, Optical Observation
  70. GRB000418, near-infrared observations
  71. Correction to IPN error box for GRB000419
  72. IPN error box for GRB000418
  73. GRB000419 [IPN Position]
  74. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  75. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  76. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  77. Budget cuts in BeppoSAX operations: impact on GRB observations
  78. GRB 000408, optical observations
  79. Refined IPN error box for GRB000408
  80. GRB 991208, UBVRI field photometry
  81. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  82. GRB000408 [IPN Position]
  83. GRB000326 Optical Observations
  84. GRB000301C - Addendum to GCN 623
  85. GRB000301C - R magnitude lower limit
  86. GRB 000323, optical observations
  87. GRB 000326: Optical Observations
  88. GRB000326, Radio observations
  89. GRB000326 [IPN Position]
  90. GRB 000307 optical observations
  91. GRB000323 [IPN Position]
  92. GRB000315 [IPN Positions]
  93. GRB 000313 - optical transient in the BATSE error box
  94. GRB000301C - B and R photometry
  95. GRB000301C - R photometry
  96. GRB 000307, Optical Observations
  97. GRB 000307, BVRI Field Photometry
  98. GRB 000301C: Optical Spectrum and Redshift
  99. GRB 000301C: Optical Spectrum and Redshift
  100. GRB 000301C: A Precise Redshift Determination

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