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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').

23836 results found.

  1. GRB 241112B: GMG Optical Upper Limit
  2. GRB 241113A: Enhanced Swift-XRT position
  3. GRB241113A: LCOGT (40-cm) optical counterpart detection
  4. GRB 241113A: Swift detection of a burst with an optical counterpart
  5. SVOM/GRM detection of a short burst from SGR 1E1841-045
  6. LIGO/Virgo/KAGRA S241111bn: Updated Sky localization
  7. GRB 241112B: AbAO optical upper limit
  8. GRB 241107A: GROWTH-India telescope optical upper limit
  9. Fermi-GBM Sub-Threshold Detection of GRB 241112B
  10. GRB 241112B: Optical afterglow detection confirmation in revisiting the Mephisto data
  11. GRB 241112B: Swift-XRT afterglow detection
  12. GRB 241112B: LCO optical detection of the SVOM/VT candidate
  13. GRB 241112B: Mephisto optical upper limits
  14. GRB 241112B: GOTO optical upper limits
  15. GRB 241107A: INTEGRAL IBIS localization
  16. LIGO/Virgo/KAGRA S241110br: NED Galaxies in the Localization Volume
  17. LIGO/Virgo/KAGRA S241109bn: ATLAS observations and discovery of the potential counterpart AT2024aawt
  18. GRB 241105A: VLT/FORS2 refined spectroscopic redshift z = 2.681
  19. LIGO/Virgo/KAGRA S241111bn: Identification of a GW compact binary merger candidate
  20. IPN triangulation of GRB 241107A (short/hard)
  21. GRB 241025C: VZLUSAT-2 detection
  22. GRB 241025A: VZLUSAT-2 detection
  23. GRB 241018A: cubesat Avion detection
  24. GRB 241030B: TESS detection of optical counterpart
  25. LIGO/Virgo/KAGRA S241110br: Updated Sky localization
  26. LIGO/Virgo/KAGRA S241110bk: 1 counterpart neutrino candidate event from an IceCube neutrino search
  27. LIGO/Virgo/KAGRA S241110br: Identification of a GW compact binary merger candidate
  28. LIGO/Virgo/KAGRA S241109bn: Upper limits from EP-WXT observations
  29. Integral GRB241109.89: Global MASTER-Net observations report
  30. LIGO/Virgo/KAGRA S241109bn: Coverage and upper limits from MAXI/GSC observations
  31. LIGO/Virgo/KAGRA S241109bn: Updated Sky localization and EM Bright Classification
  32. EP241107a: AbAO optical upper limit
  33. LIGO/Virgo/KAGRA S241109bn: Upper limits from Fermi-GBM Observations
  34. GRB 241108A: Further COLIBRÍ Upper Limits on the Optical Counterpart
  35. LIGO/Virgo/KAGRA S241109p: Updated Sky localization and Source Classification
  36. LIGO/Virgo/KAGRA S241109bn: Identification of a GW compact binary merger candidate
  37. EP241109a: confirmation of a stellar flare by BOOTES-7
  38. GRB 241108A: Swift-XRT observations
  39. LIGO/Virgo/KAGRA S241109p: Identification of a GW compact binary merger candidate
  40. EP241107a: KAIT optical observations
  41. GRB 241030A: TESS observations
  42. GRB 241108A: COLIBRÍ Upper Limits on the Optical Counterpart
  43. EP241107a: Kinder optical follow-up observations
  44. GRB 241025A: radio detection with the VLA
  45. EP241107a: AKO Optical Afterglow Follow-Up Observations
  46. EP241107a: GSP detects optical counterpart
  47. GRB 241105A: SVOM/GRM observation
  48. EP241107a: OHP/T193 photometric and spectroscopic observations
  49. GRB 241105a: PRIME near-infrared upper limits
  50. GRB 241105A: ePESSTO+ NTT optical afterglow detection
  51. EP241107a: GIT optical observations
  52. EP241107a: SVOM/C-GFT optical observations
  53. EP241107a: AKO Optical Afterglow Detection
  54. GRB 241025A: LBT optical observations
  55. GRB 241105A: VLT/FORS2 optical afterglow rapid fading
  56. GRB 241105A: Swift/UVOT Detection
  57. GRB241105A: Fermi GBM Observation of a Short Burst with Extended Emission
  58. LIGO/Virgo/KAGRA S241106ba: 1 counterpart neutrino candidate event from an IceCube neutrino search
  59. LIGO/Virgo/KAGRA S241102o: 1 counterpart neutrino candidate event from an IceCube neutrino search
  60. GRB 241105A: Swift-XRT afterglow detection
  61. GRB 241105A: VLT/FORS2 spectroscopic redshift z = 2.681
  62. GRB 241104A: Swift-XRT observations
  63. GRB 240511A: LCO upper limits
  64. GRB241104A: Fermi GBM Observation
  65. GRB 241105A: Swift/BAT-GUANO arcminute localization of a short burst
  66. GRB 241104A: SVOM/VT optical candidate
  67. GRB 241104A/EP241104a: Optical upper limits with Kinder observations
  68. GRB 241104A: COLIBRÍ Upper Limits on the Optical Counterpart
  69. EP241104a: EP detection of GRB 241104A X-ray emission
  70. GRB 241010A: host galaxy redshift z = 0.977
  71. EP241101a NUTTelA-TAO / BSTI Measurements 2024-11-02
  72. GRB 240821A: further radio observations with the VLA
  73. EP241103a: GIT optical upper limit
  74. EP241021a: OHP/T193 further optical observations
  75. LIGO/Virgo/KAGRA S241102br: OHP/T193 optical observations
  76. LIGO/Virgo/KAGRA S241102cy: Updated Sky localization
  77. LIGO/Virgo/KAGRA S241102br: Updated Sky localization
  78. EP241103a: Swift XRT detection and improved X-ray position
  79. EP241021a: continued SOAR observations
  80. EP241101a: Optical upper limits with Kinder observations
  81. EP241101a: OHP/T193 optical observations
  82. LIGO/Virgo/KAGRA S241102br: MASTER observations and OT detection
  83. LIGO/Virgo/KAGRA S241102br: EP-WXT X-ray follow-up and flux limits
  84. GRB 241030A: Swift-UVOT observations of the optical prompt flare
  85. EP241103a: GSP optical upper limit
  86. EP241103A: LCO optical observations
  87. EP241103a: an X-ray transient detected by Einstein Probe
  88. LIGO/Virgo/KAGRA S241101ee: Updated Sky localization
  89. S241102cy: Identification of a GW compact binary merger candidate
  90. LIGO/Virgo/KAGRA S241102br: NED Galaxies in the Localization Volume
  91. LIGO/Virgo/KAGRA S241102br: Identification of a GW compact binary merger candidate
  92. Kinder optical follow-up observations of EP241021a, EP241026b, and EP241030a/GRB241030A
  93. GRB241030A: OHP/T193 optical observations
  94. GRB 241101A: FRAM-ORM optical limit
  95. LIGO/Virgo/KAGRA S241101ee: Identification of a GW compact binary merger candidate
  96. GRB 241030A/EP241030a: TNOT observations of the optical counterpart
  97. EP241021a: Upper limit from Konus-Wind observations
  98. GRB 241101A: Swift-BAT refined analysis
  99. GRB 241030A: further SAO RAS optical observations
  100. GRB 241030A: Optical Observations via Virtual Telescope Project

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