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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"

36682 results found.

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

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