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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"

37753 results found.

  1. IPN localization of GRB990510
  2. GRB 990506 Radio Observations
  3. GRB 990123, optical monitoring
  4. GRB 990506: BATSE Observations
  5. GRB 990506, optical observations
  6. GRB 990510: Final BeppoSAX-WFC Coordinates
  7. GRB 990506, Optical Observations
  8. GRB 990506 optical observations
  9. GRB 990506 optical observations
  10. GRB 990506, optical observations
  11. GRB990506 observation plan
  12. Refined IPN error box for GRB990506
  13. GRB 990506: Limits on the possible optical transient
  14. GRB 990506, armchair astronomy
  15. GRB 990506, optical observations from +1 to +3 hours
  16. GRB 990506, optical observations
  17. GRB990506 observation plan
  18. New IPN/RXTE error box for GRB990506
  19. IPN localization for GRB990506
  20. GRB 970228: Redshift and properties of the host galaxy
  21. IPN localization of GRB990427
  22. GRB981220 VLBA observations
  23. GRB990321 REFINED IPN ANNULUS
  24. GRB990323 PRECISE IPN POSITION
  25. GRB990321 IPN TRIANGULATION
  26. GRB 990316 Optical Observations
  27. GRB 990316, Radio observations
  28. GRB 990316, Optical observations
  29. GRB990316, Optical observations
  30. GRB 990316 optical observations
  31. GRB990316: simultaneous optical observation
  32. ASM/IPN error box for GRB 990308 (BATSE #7457)
  33. GRB990308 not a new SGR
  34. GRB 990308a and GRB 990308b
  35. GRB990308 (Trig. 7457), optical observations
  36. GRB981220, IPN localization
  37. GRB 981220, radio observations
  38. GRB 990123, Field Photometry
  39. GRB 990217 Optical Observations
  40. GRB 990217, radio observations
  41. Optical Observations of GRB990217
  42. GRB990123: Caltech STIS Photometry and Images
  43. GRB990123 observations
  44. GRB990123, Optical Observation
  45. GRB 990123: Discovery of the Probable Host Galaxy
  46. GRB 990123: Reduced HST Images
  47. For Immediate Posting to GCN - HST Data GRB 990123 Available
  48. GRB19990123 observations
  49. GRB 990123: BVRI standards in the field
  50. GRB 990123: Updated Keck Spectroscopy Results
  51. GRB981220, field photometry
  52. GRB 990123 NOT Spectrum Update
  53. GRB990123, Optical observation
  54. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  55. GRB 990123: Publicly available reduced HST images
  56. GRB990123, Upcoming HST Service Observations
  57. GRB 990123: New Constraints on Possible Foreground Galaxies
  58. GRB990123 Optical Observations
  59. GRB990123, Probability of gravitational lensing
  60. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  61. GRB 990123: Continued Radio Observations
  62. GRB990123, Preliminary Lens Search Results
  63. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  64. On the Lensing Interpretation of GRB 990123
  65. Search for Potential Images of GRB 990123
  66. Search for Potential Images of GRB 990123
  67. GRB990123, Optical BVRI Observations
  68. GRB 990123: near-infrared observations.
  69. GRB990123, OSSE observations
  70. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  71. "GRB 990123: New BV Observations"
  72. GRB 990123 Optical Follow-Up
  73. GRB 990123; Addendum to GCN 223
  74. GRB 990123: BATSE Observations
  75. GRB 990123 Keck Spectrum update
  76. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  77. GRB990123 Optical Observations
  78. GRB 990123 Spectroscopic Redshifts
  79. GRB 990123: New Optical Observations, Decay Measure
  80. GRB 990123 Optical Follow-Up
  81. GRB 990123: Possible Gravitationally Lensed Burst?
  82. GRB 990123 optical observations
  83. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  84. GRB 990123 radio observations
  85. GRB 990123, new radio source
  86. GRB990123, Optical observation
  87. GRB 990123: Optical Decay Slope
  88. GRB 990123 r-band photometry
  89. GRB 990123 Optical Follow-up
  90. GRB990123, early optical counterpart detection
  91. GRB990123 Optical Observation
  92. GRB 990123: Bright New Source, Possible Optical Transient
  93. GRB 990123, Radio observations
  94. SN 1999E & GRB 980919
  95. Possible identification of SN1999E with GRB980910
  96. Optical Observations of GRB 981220
  97. GRB 981226: radio variable
  98. GRB981220
  99. GRB981220, Optical Observations
  100. GRB 981220 Optical observations

Advanced

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