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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"

26303 results found.

  1. IPN localization for GRB990506
  2. GRB 970228: Redshift and properties of the host galaxy
  3. IPN localization of GRB990427
  4. GRB981220 VLBA observations
  5. GRB980425 Optical observations of exponential decline at late time
  6. GRB990321 IPN TRIANGULATION
  7. GRB 990316, Radio observations
  8. GRB 990316, Optical observations
  9. GRB 990316 optical observations
  10. GRB990316: simultaneous optical observation
  11. ASM/IPN error box for GRB 990308 (BATSE #7457)
  12. GRB990308 (Trig. 7457), optical observations
  13. GRB990308, Possible new SGR~0209+70
  14. GRB981220, IPN localization
  15. GRB 981220, radio observations
  16. BATSE Resumes Normal Operations
  17. BATSE Flight Anomaly
  18. GRB990217: BeppoSAX/GRBM data
  19. Optical Observations of GRB990217
  20. GRB990123: Caltech STIS Photometry and Images
  21. GRB990123 observations
  22. GRB990123, Optical Observation
  23. GRB 990123: Discovery of the Probable Host Galaxy
  24. GRB 990123: Reduced HST Images
  25. For Immediate Posting to GCN - HST Data GRB 990123 Available
  26. GRB19990123 observations
  27. GRB 990123: Updated Keck Spectroscopy Results
  28. GRB990123, Optical observation
  29. GRB 990123: Publicly available reduced HST images
  30. GRB 990123: New Constraints on Possible Foreground Galaxies
  31. GRB990123, Probability of gravitational lensing
  32. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  33. GRB 990123: Continued Radio Observations
  34. GRB990123, Preliminary Lens Search Results
  35. On the Lensing Interpretation of GRB 990123
  36. Search for Potential Images of GRB 990123
  37. Search for Potential Images of GRB 990123
  38. GRB 990123: near-infrared observations.
  39. GRB990123, OSSE observations
  40. GRB990123: NIR Observation
  41. "GRB 990123: New BV Observations"
  42. GRB 990123 Optical Follow-Up
  43. GRB 990123; Addendum to GCN 223
  44. GRB 990123: BATSE Observations
  45. GRB 990123 Keck Spectrum update
  46. GRB990123 IPN annulus
  47. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  48. GRB990123 Optical Observations
  49. GRB 990123 Spectroscopic Redshifts
  50. GRB 990123: New Optical Observations, Decay Measure
  51. GRB 990123: Possible Gravitationally Lensed Burst?
  52. GRB990123, optical observation
  53. GRB 990123 radio observations
  54. GRB990123, Optical observation
  55. GRB 990123: Optical Decay Slope
  56. GRB 990123 r-band photometry
  57. GRB 990123 Optical Follow-up
  58. GRB990123, early optical counterpart detection
  59. GRB990123 Optical Observation
  60. GRB 990123: Bright New Source, Possible Optical Transient
  61. GRB990123, BeppoSAX WFC detection and NFI planned follow-up
  62. SN 1999E & GRB 980919
  63. Possible identification of SN1999E with GRB980910
  64. Optical Observations of GRB 981220
  65. GRB981220
  66. GRB981220, Correction to GCN 179
  67. GRB 981220 Optical observations
  68. GRB 981226 Optical Observations
  69. GRB 980613: Spectroscopy of the host galaxy
  70. GRB981226, sub-millimeter observations
  71. GRB 981220 and GRB 981226, optical observations
  72. GRB981226 Optical Observations
  73. GRB981226 BeppoSAX follow up
  74. GRB 981226 radio observations
  75. GRB 981226
  76. GRB 981226 optical observations
  77. radio observations of GRB 981226
  78. GRB981220 B, R and I band observations
  79. Optical Observations of GRB981226
  80. GRB981226, BeppoSAX Christmas GRB
  81. GRB 981226 - Infrared Observations
  82. GRB 981220
  83. GRB 981220, radio observations
  84. GRB981226 Optical Observation
  85. GRB981220 I-band Observations
  86. GRB981220 Optical Observations
  87. GRB 981220
  88. GRB 981220, optical observations
  89. GRB 980326/Host Galaxy
  90. GRB981220 IPN error box
  91. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  92. BeppoSAX NFI Observation of GRB980425
  93. GRB980329 R,I flux calibration and R,I,K upper limits
  94. GRB980425: X-ray revised positions
  95. GRB 980923 BATSE Observations
  96. SGR1900+14, BeppoSAX-GRBM observations
  97. GRB980703 Very Long Baseline Interferometry
  98. GRB970508 optical observations
  99. GRB971214, association with a Galactic star?
  100. Optical Observations of the Host Galaxy of GRB 980519

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