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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"

35949 results found.

  1. GRB 990506, optical observations
  2. GRB 990510: Final BeppoSAX-WFC Coordinates
  3. GRB 990506, Optical Observations
  4. GRB 990506 optical observations
  5. GRB 990506 optical observations
  6. GRB 990506, optical observations
  7. GRB990506 observation plan
  8. Refined IPN error box for GRB990506
  9. GRB 990506: Limits on the possible optical transient
  10. GRB 990506, armchair astronomy
  11. GRB 990506, optical observations from +1 to +3 hours
  12. GRB 990506, optical observations
  13. GRB990506 observation plan
  14. New IPN/RXTE error box for GRB990506
  15. IPN localization for GRB990506
  16. GRB 970228: Redshift and properties of the host galaxy
  17. IPN localization of GRB990427
  18. GRB981220 VLBA observations
  19. GRB990321 REFINED IPN ANNULUS
  20. GRB990323 PRECISE IPN POSITION
  21. GRB990321 IPN TRIANGULATION
  22. GRB 990316 Optical Observations
  23. GRB 990316, Radio observations
  24. GRB 990316, Optical observations
  25. GRB990316, Optical observations
  26. GRB 990316 optical observations
  27. GRB990316: simultaneous optical observation
  28. ASM/IPN error box for GRB 990308 (BATSE #7457)
  29. GRB990308 not a new SGR
  30. GRB 990308a and GRB 990308b
  31. GRB990308 (Trig. 7457), optical observations
  32. GRB981220, IPN localization
  33. GRB 981220, radio observations
  34. GRB 990123, Field Photometry
  35. GRB 990217 Optical Observations
  36. GRB 990217, radio observations
  37. Optical Observations of GRB990217
  38. GRB990123: Caltech STIS Photometry and Images
  39. GRB990123 observations
  40. GRB990123, Optical Observation
  41. GRB 990123: Discovery of the Probable Host Galaxy
  42. GRB 990123: Reduced HST Images
  43. For Immediate Posting to GCN - HST Data GRB 990123 Available
  44. GRB19990123 observations
  45. GRB 990123: BVRI standards in the field
  46. GRB 990123: Updated Keck Spectroscopy Results
  47. GRB981220, field photometry
  48. GRB 990123 NOT Spectrum Update
  49. GRB990123, Optical observation
  50. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  51. GRB 990123: Publicly available reduced HST images
  52. GRB990123, Upcoming HST Service Observations
  53. GRB 990123: New Constraints on Possible Foreground Galaxies
  54. GRB990123 Optical Observations
  55. GRB990123, Probability of gravitational lensing
  56. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  57. GRB 990123: Continued Radio Observations
  58. GRB990123, Preliminary Lens Search Results
  59. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  60. On the Lensing Interpretation of GRB 990123
  61. Search for Potential Images of GRB 990123
  62. Search for Potential Images of GRB 990123
  63. GRB990123, Optical BVRI Observations
  64. GRB 990123: near-infrared observations.
  65. GRB990123, OSSE observations
  66. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  67. "GRB 990123: New BV Observations"
  68. GRB 990123 Optical Follow-Up
  69. GRB 990123; Addendum to GCN 223
  70. GRB 990123: BATSE Observations
  71. GRB 990123 Keck Spectrum update
  72. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  73. GRB990123 Optical Observations
  74. GRB 990123 Spectroscopic Redshifts
  75. GRB 990123: New Optical Observations, Decay Measure
  76. GRB 990123 Optical Follow-Up
  77. GRB 990123: Possible Gravitationally Lensed Burst?
  78. GRB 990123 optical observations
  79. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  80. GRB 990123 radio observations
  81. GRB 990123, new radio source
  82. GRB990123, Optical observation
  83. GRB 990123: Optical Decay Slope
  84. GRB 990123 r-band photometry
  85. GRB 990123 Optical Follow-up
  86. GRB990123, early optical counterpart detection
  87. GRB990123 Optical Observation
  88. GRB 990123: Bright New Source, Possible Optical Transient
  89. GRB 990123, Radio observations
  90. SN 1999E & GRB 980919
  91. Possible identification of SN1999E with GRB980910
  92. Optical Observations of GRB 981220
  93. GRB 981226: radio variable
  94. GRB981220
  95. GRB981220, Optical Observations
  96. GRB 981220 Optical observations
  97. GRB 981226 Optical Observations
  98. GRB 980613: Spectroscopy of the host galaxy
  99. GRB981226, sub-millimeter observations
  100. GRB981220, sub-millimeter observations

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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