Skip to main content
New Announcement Feature, Code of Conduct, Circular Revisions. 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').

823 results found.

  1. Fermi-LAT Gamma-ray Observations of IceCube-200107A
  2. IceCube-200107A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  3. LIGO/Virgo S200105ae: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  4. Fermi-LAT Gamma-ray Observations of IceCube-191231A
  5. IceCube-191231A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  6. Fermi-LAT Gamma-ray Observations of IceCube-191215A
  7. LIGO/Virgo S191215w: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  8. LIGO/Virgo S191215w: Identification of a GW compact binary merger candidate
  9. IceCube-191215A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  10. LIGO/Virgo S191213g: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  11. LIGO/Virgo S191204r: No counterpart candidates in Fermi-LAT observations
  12. LIGO/Virgo S191205ah: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  13. IceCube-191204A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  14. LIGO/Virgo S191204r: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  15. Fermi-LAT Gamma-ray Observations of IceCube-191119A
  16. IceCube-191119A - No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  17. LIGO/Virgo S191110af: Potential pulsar counterparts
  18. Konus-Wind observation of the recent SGR 1935+2154 activity
  19. LIGO/Virgo S191110af: No counterpart candidates in INTEGRAL SPI-ACS, and IBIS prompt observation
  20. LIGO/Virgo S191110af: No counterpart candidates in INTEGRAL SPI-ACS, prompt observation
  21. LIGO/Virgo S191109d: No counterpart candidates in INTEGRAL SPI-ACS,prompt observation
  22. LIGO/Virgo S191105e: No counterpart candidates in INTEGRAL SPI-ACS and,IBIS prompt observation
  23. Swift trigger 933276 MASTER observation
  24. Trigger 933285: Swift detection of the brightest burst so far from SGR 1935+2154
  25. Trigger 933276: Swift detection of further activity from SGR 1935+2154
  26. Fermi GBM GRB 191104C (trigger 594592184 / 191104854) is not a GRB
  27. Fermi GBM GRBs 191104 A, B, C and triggers 594534420/191104185 and 594563923/191104527 are not GRBs
  28. SGR 1935+2154: Swift-BAT refined analysis
  29. GRB 191104B/GRB 191104C are SGR 1935+2154
  30. Trigger 933083: Swift detection of SGR 1935+2154
  31. Fermi GBM triggers 594523229/191104056 and 594528816/191104120 are not GRBs
  32. Fermi/GBM observation of a bright burst from magnetar SGR 1935+2154
  33. IceCube-191001A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  34. LIGO/Virgo S190930t: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  35. LIGO/Virgo S190930s: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  36. Fermi-LAT Gamma-ray Observations of IceCube-190922B
  37. LIGO/Virgo S190924h: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  38. LIGO/Virgo S190923y: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  39. IceCube-190922A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  40. HAWC-190916A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  41. LIGO/Virgo S190915ak: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  42. LIGO/Virgo S190910h: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  43. LIGO/Virgo S190910d: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  44. LIGO/Virgo S190901ap: No counterpart candidates in INTEGRAL SPI-ACS,prompt observation
  45. LIGO/Virgo S190828l: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  46. LIGO/Virgo S190828j: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  47. Fermi GBM-190816: Location-dependent upper limits from INTEGRAL/SPI-ACS prompt observation
  48. IceCube-190819A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  49. HAWC-190806A: upper limits from INTEGRAL SPI-ACS and IBIS prompt observation
  50. IceCube 190730A: one weakly associated counterpart candidates in INTEGRAL SPI-ACS, and IBIS prompt observation
  51. Fermi-LAT Gamma-ray Observations of IceCube-190712A
  52. Fermi-LAT Gamma-ray Observations of IceCube-190504A
  53. LIGO/Virgo S190426c: Fermi-LAT search for a high-energy gamma-ray counterpart
  54. LIGO/Virgo S190425z: Las Cumbres Observatory Galaxy Targeted Counterpart Search
  55. GRB 190326A: Swift XRT and UVOT follow-up observations
  56. GRB 190326A: Swift-BAT refined analysis - a soft-short GRB or an SGR
  57. INTEGRAL observations of the events in the GWTC-1 catalog
  58. GRB 181201A: a long GRB detected by INTEGRAL
  59. GRB 180828A: Swift detection of a GRB or possible Galactic Transient Swift J1754.9-2548
  60. GRB 180809A: further Swift/XRT observations
  61. GRB 180701A/MAXI J2119-045: CALET Gamma-Ray Burst Monitor data search
  62. GRB 180728A: VLT/X-shooter redshift of a nearby energetic GRB
  63. Fermi GBM triggers 552488966/180705548 and 552490104/180705561 are not GRBs
  64. GRB 180701A: MAXI/GSC detection
  65. Fermi-GBM Detection of possible burst from AXP CXOU J164710.2-455216/PSR J1647-4552
  66. Swift trigger 781740: Further analysis from Swift and Fermi/GBM
  67. Fermi-GBM Detection of possible burst from AXP CXOU J164710.2-455216/PSR J1647-4552
  68. Trigger 780207: Swift triggers again on AXP CXOU J164710.2-455216/PSR J1647-4552
  69. LIGO/Virgo G298048: Chandra X-ray Update on GW170817
  70. LIGO/Virgo G298048: Discovery of X-ray emission from SSS17a in NGC4993
  71. LIGO/Virgo G298936: Astrosat CZTI upper limits
  72. LIGO/Virgo G298048: INTEGRAL pointed follow-up observations
  73. LIGO/Virgo G298048: Chandra X-ray observations
  74. GRB170730A detecetd by INTEGRAL. Refined analysis
  75. Fermi GBM Detection of possible burst from AXP 4U 0142+61
  76. GRB 170524A: Swift detection of a burst (or possible new SGR)
  77. LIGO/Virgo G275697: DLT40 follow-up observation
  78. LIGO/Virgo G268556/GW170104: Lomonosov BDRG observations
  79. GRB 160821B: Swift-BAT refined analysis
  80. GBM observation of SGR-like burst from the direction of PSR 1119-6127
  81. Trigger 706396: Swift detection of a short burst from PSR 1119-6127
  82. GRB 160703, GRB 160705, GRB 160720, SGR1935+2154: First SGRs and GRBs detected by Lomonosov.
  83. SGR 1935+2154: CALET Gamma-Ray Burst Monitor detections
  84. Konus-Wind observation of a bright burst from SGR 1935+2154
  85. SGR 1935+2154: AMI 15 GHz upper limits of the magnetar during outburst
  86. Fermi/GBM observation of a bright burst from magnetar SGR 1935+2154
  87. Swift-BAT refined analysis on the bright event from SGR 1935+2154
  88. Trigger 701590: Swift detection of a bright outburst from SGR 1935+2154
  89. GROND observations of GRB 160622A/SNR RCW 103/SGR 1617-5103
  90. Trigger 701182: Swift detection of SGR 1935+2154
  91. SGR 1617-5103 (BAT trigger 700791): Enhanced Swift-XRT position.
  92. Swift-BAT refined analysis of the recent outburst from SGR 1617-5103 (a.k.a. 1E 161348-5055 and 2E 1613.5-5053)
  93. Fermi GBM Trigger 160622573 is not a GRB
  94. GRB 160622A: Swift detection of a possible short GRB or a new SGR
  95. More FERMI GBM bursts from the magnetar SGR 1935+2154
  96. SGR 1935+2154: MAXI/GSC detection
  97. Fermi GBM trigger 488128598/160620637 is not a GRB
  98. Fermi GBM trigger 487974449/160618852 is not a GRB
  99. Trigger 689353 (possible transient near Sgr A*), Swift-BAT refined analysis
  100. Trigger 689353: Swift detection of a transient near Sgr A*

Advanced

Download all Circulars as a .tar.gz archive:
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