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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"

33674 results found.

  1. GRB990123, HST/STIS observations of the host galaxy
  2. GRB 000615, near-infrared observations
  3. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  4. GRB000616 [IPN Position]
  5. GRB000615B [IPN Position]
  6. GRB000615, further R-band photometry
  7. GRB 000615: NIR observations
  8. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  9. GRB000615, R-band photometry
  10. GRB980425, HST/STIS observations of the host galaxy
  11. GRB000615: BeppoSAX GRB Alert
  12. The Hosts of GRB 980703 and GRB 971214
  13. GRB 000301C: Further Late-Time HST/STIS observations
  14. GRB000528: follow-up X-ray measurements and update of IPN annulus
  15. GRB980519, HST/STIS observations of the host galaxy
  16. GRB000607, Radio Observations
  17. GRB000604 - Optical observations
  18. GRB000607, A SHORT, HARD BURST
  19. GRB000604, optical observations
  20. GRB000528, optical observations at ESO
  21. GRB 000604 optical observations
  22. GRB 000418: Detection of the Host Galaxy
  23. GRB000604, optical observations, comparison with DPOSS
  24. GRB000604 [IPN Position]
  25. X-ray Afterglow of GRB 000529
  26. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  27. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  28. IPN localization and time history of GRB000528
  29. New IPN localization of GRB000529
  30. GRB 000528 - WFC measurements
  31. GRB000528: BeppoSAX GRBM observations
  32. GRB 000528 Optical Observations
  33. GRB000519, BVRI field photometry
  34. IPN triangulation of GRB000519
  35. IPN triangulation of GRB000516
  36. Re: GRB000508B : Optical observations
  37. GRB 000418, Optical observation
  38. GRB000508B, optical photometry
  39. GRB000508B, BVR field photometry
  40. Possible GRB-related phenomenon
  41. RXTE/ASM and IPN localization of GRB 000508B
  42. GRB000424, UBVRI field photometry
  43. GRB 000424 Optical Observations
  44. GRB000418, UBVRI field photometry update
  45. The redshift of GRB 000418
  46. GRB 000429, optical observation
  47. GRB 000429, UBVRI field photometry
  48. IPN localization of GRB000429
  49. GRB 000418, UBVRI field photometry
  50. GRB000418, K'-band photometry
  51. GRB 000418, Optical Observation
  52. GRB 000418, optical observation
  53. GRB000424 Optical Observations
  54. GRB 000418, Optical Observation
  55. GRB 000424, Optical Observations
  56. GRB 000418, Optical Observation
  57. GRB000418, near-infrared observations
  58. Correction to IPN error box for GRB000419
  59. IPN error box for GRB000418
  60. GRB000419 [IPN Position]
  61. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  62. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  63. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  64. Budget cuts in BeppoSAX operations: impact on GRB observations
  65. GRB 000408, optical observations
  66. Refined IPN error box for GRB000408
  67. GRB 991208, UBVRI field photometry
  68. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  69. GRB000408 [IPN Position]
  70. GRB000326 Optical Observations
  71. GRB000301C - Addendum to GCN 623
  72. GRB000301C - R magnitude lower limit
  73. GRB 000323, optical observations
  74. GRB 000326: Optical Observations
  75. GRB000326, Radio observations
  76. GRB000326 [IPN Position]
  77. GRB 000307 optical observations
  78. GRB000323 [IPN Position]
  79. GRB000315 [IPN Positions]
  80. GRB 000313 - optical transient in the BATSE error box
  81. GRB000301C - B and R photometry
  82. GRB000301C - R photometry
  83. GRB 000307, Optical Observations
  84. GRB 000307, BVRI Field Photometry
  85. GRB 000301C: Optical Spectrum and Redshift
  86. GRB 000301C: Optical Spectrum and Redshift
  87. GRB 000301C: A Precise Redshift Determination
  88. GRB 000301C, Optical Observation
  89. GRB 000301C: HST/STIS-PRISM NUV-MAMA spectroscopy
  90. GRB 000301C: HST/STIS CCD Imaging of the field
  91. IPN error box for GRB000307
  92. GRB 000301c: K' observations
  93. GRB000301C, optical R-band observations
  94. GRB000301c - R photometry and nearby faint source confirmation
  95. GRB 000301C, Optical Observation
  96. GRB 000301c: K' observations
  97. GRB 000301C Optical Observations
  98. GRB 000301C: K' Observations
  99. GRB000301C - Host galaxy not detected in R (?)
  100. GRB000301C optical observations

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