Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

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"

42741 results found.

  1. GRB 990123: New Constraints on Possible Foreground Galaxies
  2. GRB990123 Optical Observations
  3. GRB990123, Probability of gravitational lensing
  4. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  5. GRB 990123: Continued Radio Observations
  6. GRB990123, Preliminary Lens Search Results
  7. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  8. On the Lensing Interpretation of GRB 990123
  9. Search for Potential Images of GRB 990123
  10. Search for Potential Images of GRB 990123
  11. GRB990123, Optical BVRI Observations
  12. GRB 990123: near-infrared observations.
  13. GRB990123, OSSE observations
  14. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  15. GRB990123: NIR Observation
  16. GRB990123, ASCA X-ray observation of afterglow
  17. "GRB 990123: New BV Observations"
  18. GRB 990123 Optical Follow-Up
  19. GRB 990123: BATSE Observations
  20. GRB 990123 Keck Spectrum update
  21. GRB990123 IPN annulus
  22. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  23. GRB990123 Optical Observations
  24. GRB 990123 Spectroscopic Redshifts
  25. GRB 990123: New Optical Observations, Decay Measure
  26. GRB 990123 Optical Follow-Up
  27. GRB 990123: Possible Gravitationally Lensed Burst?
  28. GRB990123, optical observation
  29. GRB 990123 optical observations
  30. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  31. GRB 990123 radio observations
  32. GRB 990123, new radio source
  33. GRB990123 optical observations
  34. GRB990123, Optical observation
  35. GRB 990123: Optical Decay Slope
  36. GRB 990123 r-band photometry
  37. GRB 990123 Optical Follow-up
  38. GRB990123, early optical counterpart detection
  39. GRB990123 Optical Observation
  40. GRB 990123: Bright New Source, Possible Optical Transient
  41. GRB 990123, Radio observations
  42. GRB990123, BeppoSAX WFC detection and NFI planned follow-up
  43. SN 1999E & GRB 980919
  44. Possible identification of SN1999E with GRB980910
  45. Optical Observations of GRB 981220
  46. GRB 981226: radio variable
  47. GRB981220
  48. GRB981220, Correction to GCN 179
  49. GRB981220, Optical Observations
  50. GRB 981220 Optical observations
  51. GRB 981226 Optical Observations
  52. GRB 980613: Spectroscopy of the host galaxy
  53. GRB981226, sub-millimeter observations
  54. GRB981220, sub-millimeter observations
  55. GRB 981220 and GRB 981226, optical observations
  56. GRB981226 Optical Observations
  57. GRB 981226 radio observations
  58. GRB 981226
  59. GRB 981226 optical observations
  60. radio observations of GRB 981226
  61. GRB981220 B, R and I band observations
  62. GRB981226, BeppoSAX-NFI follow-up
  63. Optical Observations of GRB981226
  64. GRB 981220:Optical Observations
  65. GRB 981220 optical R and I observations
  66. GRB981226, BeppoSAX Christmas GRB
  67. GRB 981226 - Infrared Observations
  68. GRB 981226 optical observations
  69. GRB 981220
  70. GRB 981220, radio observations
  71. GRB981226 Optical Observation
  72. GRB 981220, radio observations
  73. GRB 981220: BeppoSAX/GRBM results
  74. GRB981220 I-band Observations
  75. GRB981220 Optical Observations
  76. GRB 981220
  77. GRB 981220, optical observations
  78. GRB 980326/Host Galaxy
  79. GRB981220 IPN error box
  80. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  81. BeppoSAX NFI Observation of GRB980425
  82. GRB980329 R,I flux calibration and R,I,K upper limits
  83. GRB980425 Optical Follow-up
  84. GRB980425: X-ray revised positions
  85. GRB 980923 BATSE Observations
  86. SGR1900+14, BeppoSAX-GRBM observations
  87. GRB980703 Very Long Baseline Interferometry
  88. GRB970508 optical observations
  89. GRB971214, association with a Galactic star?
  90. Optical Observations of the Host Galaxy of GRB 980519
  91. GRB980519, Optical Observations
  92. GRB980703, Host galaxy multicolor photometry
  93. GRB980703 - BeppoSAX/GRBM detection
  94. GRB 980703 (NFI observations)
  95. GRB980703 optical photometry
  96. GRB 980703: BATSE Observations
  97. GRB980703 optical observations
  98. GRB980703: Radio transient
  99. GRB980703 H-band Observations
  100. GRB 980703: Spectrum of the proposed optical counterpart

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov