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"

16173 results found.

  1. GRB 040323, a dark GRB ?
  2. GRB040223, improved XMM position
  3. GRB 031203: spectoscopic evidence for a 1998bw-like SN
  4. MASTER: RXTE GRB040308 optical observation
  5. RXTE GRB040229 optical observation: no candidate
  6. GRB 040228 Optical observations
  7. GRB040228 : KISO optical follow-up observation
  8. GRB 040228 (=H3066?,=H3067?): A Long GRB Localized by the HETE-2 WXM
  9. GRB 040223 : Optical observation (non-detection)
  10. GRB031111, optical observations
  11. GRB031220: 2nd Chandra observation and X-ray afterglow candidate
  12. GRB040106: refined X-ray transient position
  13. SN 2003dh/GRB030329 late-time optical spectroscopy
  14. GRB040106, Radio Observations
  15. GRB040106, likely optical afterglow
  16. GRB040106: Second Epoch Optical Observations
  17. GRB 031220: Optical observations of Chandra X-ray sources
  18. GRB040106: optical observations with REM+ROSS
  19. GRB 040106: Optical observations
  20. GRB031220(=H2976): TNG R-band Observation of the Chandra X-ray Sources
  21. GRB 031220 : Kyoto Optical Observation
  22. GRB 031220: Optical observation at Tokyo Tech
  23. GRB031220: ROTSE-IIIb Optical Limits
  24. GRB031220 : Optical Observation of Lulin Observatory
  25. GRB 031203 I-band monitoring
  26. GRB 031203: Discovery of a dust echo
  27. GRB 031203: SMARTS optical monitoring
  28. GRB 031203: Optical/IR Astrometry
  29. IPN/HETE localization of GRB031203B (=H2949; large error box)
  30. GRB031203 : Optical Observation of Lulin Observatory
  31. GRB031203: Optical Observations
  32. GRB 031203: Optical/IR SMARTS Observations
  33. GRB031111A, prompt optical observations
  34. GRB 031111B (= H2925) : Kyoto Optical Observation
  35. GRB 031111: Optical observations
  36. GRB 031111, optical observations
  37. SN 2003jd (SN/GRB?) -- X-ray Observations
  38. XRF031109 (=H2919): A very long XRF localized by HETE
  39. Lulin optical follow-up observations of GRB031026
  40. GRB 031026 (=H2882): Evidence for High Redshift from Prompt
  41. Peculiar Type Ic SN 2003jd (SN/GRB?), optical spectrum
  42. GRB031026 (=H2882): A Long, Hard Spectrum Burst Localized by HETE
  43. GRB031026 : KISO optical follow-up observation
  44. IPN detection of continued activity from SGR1806-20
  45. XRF 030723: Subaru Optical Observations
  46. XRF 030723: Detection of the likely host galaxy
  47. XRF030824 (=H2821): An X-Ray Flash Localized by the HETE WXM
  48. XRF030823 (=H2818): An X-Ray Flash Localized by the HETE WXM and SXC
  49. GRB030913: Subaru Optical Observations
  50. GRB 030913: ROTSE-3c Optical Observations
  51. GRB030913, candidate afterglow observations
  52. GRB 030913, optical candidate
  53. GRB030913: AAVSO optical observations
  54. GRB030913 (=H2849): Confirmation of the Flight Localization
  55. Magellan Observations of GRB030725 (=H2779)
  56. GRB030913 (=H2849): A GRB Possibly Localized by HETE
  57. GRB 030913: Optical limit at RIKEN
  58. XRF030824: Optical observations
  59. IBAS detection of bursts from SGR 1806-20
  60. XRF030824: Second-epoch Palomar observations
  61. XRF030824: optical observations
  62. GRB030823: optical observations
  63. GRB030823: Palomar observations
  64. GRB030823: optical observation at Tokyo Tech
  65. GRB 030821(=H2814): A Faint, Long GRB Localized by the HETE WXM and the IPN
  66. IPN detection of continued activity from SGR1806-20
  67. GRB 030817 = H2808 TAROT optical observations
  68. SGR 1808-20 (=H2802): A Possible new SGR
  69. GRB 021206 Optical Observations
  70. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  71. XRF 030723: Detection of a rebrightening in the optical afterglow
  72. GRB030725: Optical observations
  73. XRF030723, BVRcIc field photometry update
  74. GRB021206 optical counterpart upper limit
  75. IPN triangulation of GRB030725 (=H2779; small error box)
  76. XRF030723 (=H2777): Second Epoch Magellan Observations
  77. GRB 030725: optical observations.
  78. GRB030725, optical transient observations
  79. XRF030723 Radio Observations
  80. XRF 030723: confirmation of fading optical counterpart
  81. XRF030723(=H2777): Chandra Observations
  82. Magellan Observations of XRF030723 (=H2777)
  83. GRB030723: Upper limits from historical observations
  84. GRB030725, possible optical transient
  85. XRF030723: Palomar observations and proposed counterpart
  86. GRB030725 (=H2779): A Bright GRB Localized by HETE
  87. XRF030723: optical observations
  88. XRF030723 (= H2777): Chandra Observations Scheduled
  89. XRF030723, BVRcIc field photometry
  90. XRF 030723, optical observations
  91. XRF030723, optical observations
  92. XRF 030723, optical observations
  93. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  94. GRB030723, optical observations
  95. H2768, H2770, and H2771: Three Bursts from SGR1806-20
  96. GRB030329: Subaru Optical Spectroscopy
  97. GRB030329: RTT150 optical observations
  98. GRBlog: Compilation of all GCN Circ. data
  99. GRB030329, optical observation in May
  100. GRB030418: R optical observations

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