Light curves and photometric parameters of the comets C/1999 S4 (LINEAR), C/2001 Q4 (NEAT), C/2002 T7 (LINEAR), C/2002 V1 (NEAT), C2004 Q2 (Machholz), and 153P/2002 C1 (Ikeya-Zhang)

Churyumov, K. I.; Filonenko, V. S.; Chubko, L. S.

doi:10.3103/s0884591308020062

Cited by 1 publication

(2 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, they concluded that this comet was definitely more active before than after perihelion and that power-law fitting gives significantly different powerlaw slopes for pre-and post-perihelion changes in the water production rate with the heliocentric distance r. They found that the best-fit power-law variations in the water production rate of C/2001 Q4 are proportional to r −2.2 and r −1.7 for the pre-and post-perihelion data, separately. This means that a power-law function of water production rate generally seems to be steeper A119, page 8 of 12 before perihelion passage than after, which is in agreement with Churyumov et al (2008). However, Combi et al (2009) reported that comet NEAT "showed a production rate outburst about 30 days before perihelion (15 April 2004) and then a large extended increase above the nominal trend from 50 to 70 days after perihelion (2004 July 5−July 25)".…”

Section: C/2001 Q4 Neatsupporting

confidence: 53%

“…Around perihelion, when the comet was closer than 1.6 AU from the Sun, the average variations in the brightness seemed to be smaller, however several local maxima and minima are visible in the light curve, for example Kammerer points to a significant minimum just before perihelion (between 20 April and 5 May) and then a sharp increase until perihelion. According to Churyumov et al (2008), the power-law slope of the brightness variation with heliocentric distance changed four times before perihelion and four times after. They also concluded that these photometric changes occurred at very similar heliocentric distances before and after perihelion.…”

Section: C/2001 Q4 Neatmentioning

confidence: 99%

See 1 more Smart Citation

Different dynamical histories for comets C/2001 Q4 and C/2002 T7?

Królikowska

Dybczyński

Sitarski

2012

A&A

View full text Add to dashboard Cite

Context. Both, C/2001 Q4 and C/2002 T7, are widely regarded in the literature as dynamically new comets that are visiting our planetary system for the first time from the Oort Cloud. Aims. We study the past dynamical evolution of these two bright comets that both have an original semimajor axis inside the so-called Oort spike (i.e. with 1/a ori < 10 −4 AU −1 ). Methods. For each comet, we constructed a dedicated grid of independent, starting, osculating swarms of 5000 orbits based on different subsets of positional data and different dependences of the non-gravitational acceleration on the heliocentric distance. We then followed numerically each swarm of non-gravitational orbits one orbital revolution into the past, taking into account both planetary and Galactic perturbations and checking for all known stellar perturbers. This method allows us to obtain the orbital elements and their uncertainties at the previous perihelion passage. Results. We find that the dedicated g(r)-like function seems to be more adequate for describing the non-gravitational effects than the standard g(r)-function in the motion of both comets, but we are able to estimate only two parameters: the scale distance r 0 , and the exponent m. We show, however, that the greatest change in the previous perihelion value relative to that obtained in the standard approach results from the type of data subset used for non-gravitational orbit determination. The form of the dependence of nongravitational acceleration on heliocentric distance is of secondary importance for both investigated comets in this context. We find that only comet C/2002 T7 passed far beyond the planetary system during its previous perihelion passage and that C/2001 Q4 was probably well inside the Saturn orbit at a previous perihelion. Conclusions. We argue that for these comets (which have long sequences of positional data), the safest method for the previous perihelion determination is to exclude data within time intervals where some local outbursts were reported. We recommend that the non-gravitational models based on data taken at larger perihelion distance are more appropriate for estimating the distance of previous perihelion passage of C/2001 Q4 and those based on a pre-perihelion data set for previous perihelion estimation of C/2002 T7. These models suggest that C/2001 Q4 passed its previous perihelion closer than 6-7 AU from the Sun, so is dynamically old, whereas C/2002 T7 at a distance larger than 400 AU, is a dynamically new comet since it overcame the Jupiter-Saturn barrier.

show abstract

Section: C/2001 Q4 Neatsupporting

confidence: 53%

Section: C/2001 Q4 Neatmentioning

confidence: 99%