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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"

36180 results found.

  1. GRB000607, optical observations
  2. GRB 000615: NIR further observations
  3. BeppoSAX ALERT: GRB000620
  4. GRB000620: BeppoSAX Alert
  5. GRB990123, HST/STIS observations of the host galaxy
  6. GRB 000615, near-infrared observations
  7. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  8. GRB000616 [IPN Position]
  9. GRB000615B [IPN Position]
  10. GRB000615, further R-band photometry
  11. GRB 000615: NIR observations
  12. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  13. GRB000615, R-band photometry
  14. GRB980425, HST/STIS observations of the host galaxy
  15. GRB000615: BeppoSAX GRB Alert
  16. The Hosts of GRB 980703 and GRB 971214
  17. GRB 000301C: Further Late-Time HST/STIS observations
  18. GRB000528: follow-up X-ray measurements and update of IPN annulus
  19. GRB980519, HST/STIS observations of the host galaxy
  20. GRB000607, Radio Observations
  21. GRB000604 - Optical observations
  22. GRB000607, A SHORT, HARD BURST
  23. GRB000604, optical observations
  24. GRB000528, optical observations at ESO
  25. GRB 000604 optical observations
  26. GRB 000418: Detection of the Host Galaxy
  27. GRB000604, optical observations, comparison with DPOSS
  28. GRB000604 [IPN Position]
  29. X-ray Afterglow of GRB 000529
  30. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  31. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  32. IPN localization and time history of GRB000528
  33. New IPN localization of GRB000529
  34. GRB 000528 - WFC measurements
  35. GRB000528: BeppoSAX GRBM observations
  36. GRB 000528 Optical Observations
  37. GRB000519, BVRI field photometry
  38. IPN triangulation of GRB000519
  39. IPN triangulation of GRB000516
  40. Re: GRB000508B : Optical observations
  41. GRB 000418, Optical observation
  42. GRB000508B, optical photometry
  43. GRB000508B, BVR field photometry
  44. Possible GRB-related phenomenon
  45. RXTE/ASM and IPN localization of GRB 000508B
  46. GRB000424, UBVRI field photometry
  47. GRB 000424 Optical Observations
  48. GRB000418, UBVRI field photometry update
  49. The redshift of GRB 000418
  50. GRB 000429, optical observation
  51. GRB 000429, UBVRI field photometry
  52. IPN localization of GRB000429
  53. GRB 000418, UBVRI field photometry
  54. GRB000418, K'-band photometry
  55. GRB 000418, Optical Observation
  56. GRB 000418, optical observation
  57. GRB000424 Optical Observations
  58. GRB 000418, Optical Observation
  59. GRB 000424, Optical Observations
  60. GRB 000418, Optical Observation
  61. GRB000418, near-infrared observations
  62. Correction to IPN error box for GRB000419
  63. IPN error box for GRB000418
  64. GRB000419 [IPN Position]
  65. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  66. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  67. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  68. Budget cuts in BeppoSAX operations: impact on GRB observations
  69. GRB 000408, optical observations
  70. Refined IPN error box for GRB000408
  71. GRB 991208, UBVRI field photometry
  72. GRB000301c results
  73. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  74. GRB000408 [IPN Position]
  75. GRB000326 Optical Observations
  76. GRB000301C - Addendum to GCN 623
  77. GRB000301C - R magnitude lower limit
  78. GRB 000323, optical observations
  79. GRB 000326: Optical Observations
  80. GRB000326, Radio observations
  81. GRB000326 [IPN Position]
  82. GRB 000307 optical observations
  83. GRB000323 [IPN Position]
  84. GRB000315 [IPN Positions]
  85. GRB 000313 - optical transient in the BATSE error box
  86. GRB000301C - B and R photometry
  87. GRB000301C - R photometry
  88. GRB 000307, Optical Observations
  89. GRB 000307, BVRI Field Photometry
  90. GRB 000301C: Optical Spectrum and Redshift
  91. GRB 000301C: Optical Spectrum and Redshift
  92. GRB 000301C: A Precise Redshift Determination
  93. GRB 000301C, Optical Observation
  94. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  95. GRB 000301C: HST/STIS CCD Imaging of the field
  96. IPN error box for GRB000307
  97. GRB 000301c: K' observations
  98. GRB000301C, optical R-band observations
  99. GRB000301c - R photometry and nearby faint source confirmation
  100. GRB 000301C, Optical Observation

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