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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"

35422 results found.

  1. GRB990308 not a new SGR
  2. GRB 990308a and GRB 990308b
  3. GRB990308 (Trig. 7457), optical observations
  4. GRB981220, IPN localization
  5. GRB 981220, radio observations
  6. GRB 990123, Field Photometry
  7. GRB 990217 Optical Observations
  8. GRB 990217, radio observations
  9. Optical Observations of GRB990217
  10. GRB990123: Caltech STIS Photometry and Images
  11. GRB990123 observations
  12. GRB990123, Optical Observation
  13. GRB 990123: Discovery of the Probable Host Galaxy
  14. GRB 990123: Reduced HST Images
  15. For Immediate Posting to GCN - HST Data GRB 990123 Available
  16. GRB19990123 observations
  17. GRB 990123: BVRI standards in the field
  18. GRB 990123: Updated Keck Spectroscopy Results
  19. GRB981220, field photometry
  20. GRB 990123 NOT Spectrum Update
  21. GRB990123, Optical observation
  22. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  23. GRB 990123: Publicly available reduced HST images
  24. GRB990123, Upcoming HST Service Observations
  25. GRB 990123: New Constraints on Possible Foreground Galaxies
  26. GRB990123 Optical Observations
  27. GRB990123, Probability of gravitational lensing
  28. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  29. GRB 990123: Continued Radio Observations
  30. GRB990123, Preliminary Lens Search Results
  31. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  32. On the Lensing Interpretation of GRB 990123
  33. Search for Potential Images of GRB 990123
  34. Search for Potential Images of GRB 990123
  35. GRB990123, Optical BVRI Observations
  36. GRB 990123: near-infrared observations.
  37. GRB990123, OSSE observations
  38. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  39. "GRB 990123: New BV Observations"
  40. GRB 990123 Optical Follow-Up
  41. GRB 990123; Addendum to GCN 223
  42. GRB 990123: BATSE Observations
  43. GRB 990123 Keck Spectrum update
  44. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  45. GRB990123 Optical Observations
  46. GRB 990123 Spectroscopic Redshifts
  47. GRB 990123: New Optical Observations, Decay Measure
  48. GRB 990123 Optical Follow-Up
  49. GRB 990123: Possible Gravitationally Lensed Burst?
  50. GRB 990123 optical observations
  51. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  52. GRB 990123 radio observations
  53. GRB 990123, new radio source
  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. GRB 990123, Radio observations
  62. SN 1999E & GRB 980919
  63. Possible identification of SN1999E with GRB980910
  64. Optical Observations of GRB 981220
  65. GRB 981226: radio variable
  66. GRB981220
  67. GRB981220, Optical Observations
  68. GRB 981220 Optical observations
  69. GRB 981226 Optical Observations
  70. GRB 980613: Spectroscopy of the host galaxy
  71. GRB981226, sub-millimeter observations
  72. GRB981220, sub-millimeter observations
  73. GRB 981220 and GRB 981226, optical observations
  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. GRB 981220:Optical Observations
  80. GRB 981220 optical R and I observations
  81. GRB981226, BeppoSAX Christmas GRB
  82. GRB 981226 - Infrared Observations
  83. GRB 981226 optical observations
  84. GRB 981220
  85. GRB 981220, radio observations
  86. GRB981226 Optical Observation
  87. GRB 981220, radio observations
  88. GRB 981220: BeppoSAX/GRBM results
  89. GRB981220 I-band Observations
  90. GRB 981220
  91. GRB 981220 Optical Observations
  92. GRB 981220, optical observations
  93. GRB 980326/Host Galaxy
  94. GRB981220 IPN error box
  95. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  96. GRB980329 R,I flux calibration and R,I,K upper limits
  97. GRB980425: X-ray revised positions
  98. GRB 980923 BATSE Observations
  99. GRB980703 Very Long Baseline Interferometry
  100. GRB970508 optical observations

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