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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"

35152 results found.

  1. GRB 990506 Radio Observations
  2. GRB 990123, optical monitoring
  3. GRB 990506: BATSE Observations
  4. GRB 990506, optical observations
  5. GRB 990510: Final BeppoSAX-WFC Coordinates
  6. GRB 990506, Optical Observations
  7. GRB 990506 optical observations
  8. GRB 990506 optical observations
  9. GRB 990506, optical observations
  10. GRB990506 observation plan
  11. Refined IPN error box for GRB990506
  12. GRB 990506: Limits on the possible optical transient
  13. GRB 990506, armchair astronomy
  14. GRB 990506, optical observations from +1 to +3 hours
  15. GRB 990506, optical observations
  16. GRB990506 observation plan
  17. New IPN/RXTE error box for GRB990506
  18. IPN localization for GRB990506
  19. GRB 970228: Redshift and properties of the host galaxy
  20. IPN localization of GRB990427
  21. GRB981220 VLBA observations
  22. GRB990321 REFINED IPN ANNULUS
  23. GRB990323 PRECISE IPN POSITION
  24. GRB990321 IPN TRIANGULATION
  25. GRB 990316 Optical Observations
  26. GRB 990316, Radio observations
  27. GRB 990316, Optical observations
  28. GRB990316, Optical observations
  29. GRB 990316 optical observations
  30. GRB990316: simultaneous optical observation
  31. ASM/IPN error box for GRB 990308 (BATSE #7457)
  32. GRB990308 not a new SGR
  33. GRB 990308a and GRB 990308b
  34. GRB990308 (Trig. 7457), optical observations
  35. GRB981220, IPN localization
  36. GRB 981220, radio observations
  37. GRB 990123, Field Photometry
  38. GRB 990217 Optical Observations
  39. GRB 990217, radio observations
  40. Optical Observations of GRB990217
  41. GRB990123: Caltech STIS Photometry and Images
  42. GRB990123 observations
  43. GRB990123, Optical Observation
  44. GRB 990123: Discovery of the Probable Host Galaxy
  45. GRB 990123: Reduced HST Images
  46. For Immediate Posting to GCN - HST Data GRB 990123 Available
  47. GRB19990123 observations
  48. GRB 990123: BVRI standards in the field
  49. GRB 990123: Updated Keck Spectroscopy Results
  50. GRB981220, field photometry
  51. GRB 990123 NOT Spectrum Update
  52. GRB990123, Optical observation
  53. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  54. GRB 990123: Publicly available reduced HST images
  55. GRB990123, Upcoming HST Service Observations
  56. GRB 990123: New Constraints on Possible Foreground Galaxies
  57. GRB990123 Optical Observations
  58. GRB990123, Probability of gravitational lensing
  59. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  60. GRB 990123: Continued Radio Observations
  61. GRB990123, Preliminary Lens Search Results
  62. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  63. On the Lensing Interpretation of GRB 990123
  64. Search for Potential Images of GRB 990123
  65. Search for Potential Images of GRB 990123
  66. GRB990123, Optical BVRI Observations
  67. GRB 990123: near-infrared observations.
  68. GRB990123, OSSE observations
  69. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  70. "GRB 990123: New BV Observations"
  71. GRB 990123 Optical Follow-Up
  72. GRB 990123; Addendum to GCN 223
  73. GRB 990123: BATSE Observations
  74. GRB 990123 Keck Spectrum update
  75. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  76. GRB990123 Optical Observations
  77. GRB 990123 Spectroscopic Redshifts
  78. GRB 990123: New Optical Observations, Decay Measure
  79. GRB 990123 Optical Follow-Up
  80. GRB 990123: Possible Gravitationally Lensed Burst?
  81. GRB 990123 optical observations
  82. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  83. GRB 990123 radio observations
  84. GRB 990123, new radio source
  85. GRB990123, Optical observation
  86. GRB 990123: Optical Decay Slope
  87. GRB 990123 r-band photometry
  88. GRB 990123 Optical Follow-up
  89. GRB990123, early optical counterpart detection
  90. GRB990123 Optical Observation
  91. GRB 990123: Bright New Source, Possible Optical Transient
  92. GRB 990123, Radio observations
  93. SN 1999E & GRB 980919
  94. Possible identification of SN1999E with GRB980910
  95. Optical Observations of GRB 981220
  96. GRB 981226: radio variable
  97. GRB981220
  98. GRB981220, Optical Observations
  99. GRB 981220 Optical observations
  100. GRB 981226 Optical Observations

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