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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"

26309 results found.

  1. GRB 990506 optical observations
  2. GRB 990506 optical observations
  3. GRB990506 observation plan
  4. Refined IPN error box for GRB990506
  5. GRB 990506: Limits on the possible optical transient
  6. GRB 990506, optical observations from +1 to +3 hours
  7. IPN localization for GRB990506
  8. GRB 970228: Redshift and properties of the host galaxy
  9. IPN localization of GRB990427
  10. GRB981220 VLBA observations
  11. GRB980425 Optical observations of exponential decline at late time
  12. GRB990321 IPN TRIANGULATION
  13. GRB 990316, Radio observations
  14. GRB 990316, Optical observations
  15. GRB 990316 optical observations
  16. GRB990316: simultaneous optical observation
  17. ASM/IPN error box for GRB 990308 (BATSE #7457)
  18. GRB990308 (Trig. 7457), optical observations
  19. GRB990308, Possible new SGR~0209+70
  20. GRB981220, IPN localization
  21. GRB 981220, radio observations
  22. BATSE Resumes Normal Operations
  23. BATSE Flight Anomaly
  24. GRB990217: BeppoSAX/GRBM data
  25. Optical Observations of GRB990217
  26. GRB990123: Caltech STIS Photometry and Images
  27. GRB990123 observations
  28. GRB990123, Optical Observation
  29. GRB 990123: Discovery of the Probable Host Galaxy
  30. GRB 990123: Reduced HST Images
  31. For Immediate Posting to GCN - HST Data GRB 990123 Available
  32. GRB19990123 observations
  33. GRB 990123: Updated Keck Spectroscopy Results
  34. GRB990123, Optical observation
  35. GRB 990123: Publicly available reduced HST images
  36. GRB 990123: New Constraints on Possible Foreground Galaxies
  37. GRB990123, Probability of gravitational lensing
  38. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  39. GRB 990123: Continued Radio Observations
  40. GRB990123, Preliminary Lens Search Results
  41. On the Lensing Interpretation of GRB 990123
  42. Search for Potential Images of GRB 990123
  43. Search for Potential Images of GRB 990123
  44. GRB 990123: near-infrared observations.
  45. GRB990123, OSSE observations
  46. GRB990123: NIR Observation
  47. "GRB 990123: New BV Observations"
  48. GRB 990123 Optical Follow-Up
  49. GRB 990123; Addendum to GCN 223
  50. GRB 990123: BATSE Observations
  51. GRB 990123 Keck Spectrum update
  52. GRB990123 IPN annulus
  53. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  54. GRB990123 Optical Observations
  55. GRB 990123 Spectroscopic Redshifts
  56. GRB 990123: New Optical Observations, Decay Measure
  57. GRB 990123: Possible Gravitationally Lensed Burst?
  58. GRB990123, optical observation
  59. GRB 990123 radio observations
  60. GRB990123, Optical observation
  61. GRB 990123: Optical Decay Slope
  62. GRB 990123 r-band photometry
  63. GRB 990123 Optical Follow-up
  64. GRB990123, early optical counterpart detection
  65. GRB990123 Optical Observation
  66. GRB 990123: Bright New Source, Possible Optical Transient
  67. GRB990123, BeppoSAX WFC detection and NFI planned follow-up
  68. SN 1999E & GRB 980919
  69. Possible identification of SN1999E with GRB980910
  70. Optical Observations of GRB 981220
  71. GRB981220
  72. GRB981220, Correction to GCN 179
  73. GRB 981220 Optical observations
  74. GRB 981226 Optical Observations
  75. GRB 980613: Spectroscopy of the host galaxy
  76. GRB981226, sub-millimeter observations
  77. GRB 981220 and GRB 981226, optical observations
  78. GRB981226 Optical Observations
  79. GRB981226 BeppoSAX follow up
  80. GRB 981226 radio observations
  81. GRB 981226
  82. GRB 981226 optical observations
  83. radio observations of GRB 981226
  84. GRB981220 B, R and I band observations
  85. Optical Observations of GRB981226
  86. GRB981226, BeppoSAX Christmas GRB
  87. GRB 981226 - Infrared Observations
  88. GRB 981220
  89. GRB 981220, radio observations
  90. GRB981226 Optical Observation
  91. GRB981220 I-band Observations
  92. GRB981220 Optical Observations
  93. GRB 981220
  94. GRB 981220, optical observations
  95. GRB 980326/Host Galaxy
  96. GRB981220 IPN error box
  97. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  98. BeppoSAX NFI Observation of GRB980425
  99. GRB980329 R,I flux calibration and R,I,K upper limits
  100. GRB980425: X-ray revised positions

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