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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"

35983 results found.

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

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